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September 17, 2020
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https://www.sciencedaily.com/releases/2020/09/200917105318.htm
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Chaotic 'Lévy walks' are a good strategy for animals
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A paper published in the
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"Lévy walks" -- a type of behavior where an organism makes a mixture of small random-like movements and an occasional larger movement -- are very common in biological systems. They are seen in the behavior of many animal species including humans, as well as in reptiles, fish, birds, and even individual cells. They are different from what is called a "Brownian walk" -- which resembles the random movements of molecules in a gas or liquid, as the organism will occasionally take long movements which bring it to another location. However, the mechanisms through which these movements take place and the advantages they offer are not well understood.To tackle this, Masato S. Abe of the RIKEN Center for Advanced Intelligence Project, the author of the paper, began by creating a mathematical model that imitate the motion of the lava of a fruit fly -- a commonly used model organism -- using two oscillators, which are connected together. When the link between the oscillators was very weak, the larvae basically followed random Brownian motion, and when they were tightly linked together, the larvae just walked in straight lines. When there was a weak linkage, however, they exhibited precisely what a Lévy walk would look like.An interesting observation of the model was that Lévy walks emerged suddenly near points known as "critical points" -- places where the behavior undergoes a rapid transformation. He wondered if this could be beneficial in some way, and found that in these areas, actors were able to respond strongly to even mild environmental stimuli, so it could help animals make finely tuned decisions over whether to exploit the food in one area or explore other areas. Abe then used observations of the actual movements of fruit fly larva to show that they were indeed carrying out behavior that fit with the model."Thanks to this model, we can now explain why Lévy walks, emerging near critical points in a system, make sense for organisms performing tasks such as foraging for food, as well as searching for words in their memory. This work will also help us in the field of artificial intelligence to create autonomous agents that can behave more closely like living organisms."
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Animals
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September 16, 2020
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https://www.sciencedaily.com/releases/2020/09/200916131057.htm
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World's oldest animal sperm found in tiny crustaceans trapped in Myanmar amber
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An international collaboration between researchers at Queen Mary University of London and the Chinese Academy of Science in Nanjing has led to the discovery of world's oldest animal sperm inside a tiny crustacean trapped in amber around 100 million years ago in Myanmar.
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The research team, led by Dr He Wang of the Chinese Academy of Science in Nanjing, found the sperm in a new species of crustacean they named Myanmarcypris hui. They predict that the animals had sex just before their entrapment in the piece of amber (tree resin), which formed in the Cretaceous period.Fossilised sperm are exceptionally rare; previously the oldest known examples were only 17 million years old. Myanmarcypris hui is an ostracod, a kind of crustacean that has existed for 500 million years and lives in all kinds of aquatic environments from deep oceans to lakes and rivers. Their fossil shells are common and abundant but finding specimens preserved in ancient amber with their appendages and internal organs intact provides a rare and exciting opportunity to learn more about their evolution.Professor Dave Horne, Professor of Micropalaeontology at Queen Mary University of London said: "Analyses of fossil ostracod shells are hugely informative about past environments and climates, as well as shedding light on evolutionary puzzles, but exceptional occurrences of fossilised soft parts like this result in remarkable advances in our understanding."During the Cretaceous period in what is now Myanmar, the ostracods were probably living in a coastal lagoon fringed by trees where they became trapped in a blob of tree resin. The Kachin amber of Myanmar has previously yielded outstanding finds including frogs, snakes and a feathered dinosaur tail. Bo Wang, also of the Chinese Academy of Science in Nanjing added: "Hundreds of new species have been described in the past five years, and many of them have made evolutionary biologists re-consider long-standing hypotheses on how certain lineages developed and how ecological relationships evolved."The study, published in The new ostracod finds may be extremely small but in one sense they are giants. Males of most animals (including humans) typically produce tens of millions of really small sperm in very large quantities, but there are exceptions. Some tiny fruit flies (insects) and ostracods (crustaceans) are famous for investing in quality rather than quantity: relatively small numbers of "giant" sperm that are many times longer than the animal itself, a by-product of evolutionary competition for reproductive success. The new discovery is not only by far the oldest example of fossil sperm ever found but also shows that these ostracods had already evolved giant sperm, and specially-adapted organs to transfer them from male to female, 100 million years ago.Each ostracod is less than a millimetre long. Using X-ray microscopy the team made computer-aided 3-D reconstructions of the ostracods embedded in the amber, revealing incredible detail. "The results were amazing -- not only did we find their tiny appendages to be preserved inside their shells, we could also see their reproductive organs," added He Wang. "But when we identified the sperm inside the female, and knowing the age of the amber, it was one of those special Eureka-moments in a researcher's life."Wang's team found adult males and females but it was a female specimen that contained the sperm, indicating that it must have had sex shortly before becoming trapped in the amber. The reconstructions also revealed the distinctive muscular sperm pumps and penises (two of each) that male ostracods use to inseminate the females, who store them in bag-like receptacles until eggs are ready to be fertilised.Such extensive adaptation raises the question of whether reproduction with giant sperms can be an evolutionarily-stable character. "To show that using giant sperms in reproduction is not an extinction-doomed extravagance of evolution, but a serious long-term advantage for the survival of a species, we need to know when they first appeared" says co-author Dr Renate Matzke-Karasz of Ludwig-Maximilians-University in Munich.This new evidence of the persistence of reproduction with giant sperm for a hundred million years shows it to be a highly successful reproductive strategy that evolved only once in this group -- quite impressive for a trait that demands such a substantial investment from both males and females, especially when you consider that many ostracods can reproduce asexually, without needing males at all. "Sexual reproduction with giant sperm must be very advantageous" says Matzke-Karasz.
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Animals
| 2,020 |
September 16, 2020
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https://www.sciencedaily.com/releases/2020/09/200916131051.htm
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Tortoise hatchlings are attracted to faces from birth
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Tortoises are born with a natural preference for faces, according to new research from scientists at Queen Mary University of London, the University of Trento and the Fondazione Museo Civico Rovereto.
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The study provides the first evidence of the tendency for solitary animals to approach face-like shapes at the beginning of life, a preference only previously observed in social species such as human babies, chicks and monkeys.The researchers tested the reactions of hatchlings from five different species of tortoise to different patterned stimuli, made up of a series of blobs. They found that the tortoises consistently moved to areas with the 'face-like' configuration -- containing three blobs arranged in an upside-down triangle shape.The findings suggest that this early behaviour likely evolved in the common ancestors of mammals, reptiles and birds more than 300 million years ago.Dr Elisabetta Versace, lead author of the study from Queen Mary University of London, said: "Researchers have previously observed this spontaneous attraction to faces in social animals such as humans, monkeys and chicks. Because all these species require parental care, it was thought this early adaptation was important for helping young animals respond to their parents or other members of the same species. However, now we have shown that this behaviour is also found in solitary tortoise hatchlings, suggesting it may have evolved for another reason."Tortoises were hatched and kept away from any animal or human faces from birth until the start of the test. Each animal was then placed in the middle of a rectangular space divided into four areas containing either a face-like or control stimuli. The researchers analysed the preference of hatchlings for face-like stimuli by recording the first area the animal entered during the experimental period.Unlike birds and mammals, tortoises are solitary species -- they have no post-hatching parental care and do not form social groups as adults. Previous research has even shown that tortoise hatchlings ignore or avoid members of the same species in early life.Silvia Damini from the University of Trento, said: "It is possible that this preference for face-like stimuli enhances learning from living animals in both social and solitary species from the early stages of life. In fact, other animals can provide information on important environmental factors, such as the availability of resources."Gionata Stancher, Head of the Tortoise Sanctuary Sperimentarea (Fondazione Museo Civico Rovereto, Italy) where the experiments were conducted, said: "Being able to recognise and respond to cues associated with other living animals could help young animals acquire information vital for their survival."
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Animals
| 2,020 |
September 16, 2020
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https://www.sciencedaily.com/releases/2020/09/200916131040.htm
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A new species of spider
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During a research stay in the highlands of Colombia conducted as part of her doctorate, Charlotte Hopfe, PhD student under the supervision of Prof. Dr. Thomas Scheibel at the Biomaterials research group at the University of Bayreuth, has discovered and zoologically described a new species of spider. The previously unknown arachnids are native to the central cordillera, not far from the Pacific coast, at an altitude of over 3,500 meters above sea-level. In the magazine
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"I chose the zoological name Ocrepeira klamt in honour of Ulrike Klamt, my German teacher at high school. The enthusiasm with which she pursues her profession and the interest she shows in her students and in literature are an inspiration to me," says Charlotte Hopfe.The cordillera in Colombia is famous for its unusually large variety of species. The habitats of these species are distributed at altitudes with very different climatic conditions, vegetation, and ecosystems. The Bayreuth researcher has collected and zoologically determined specimens of more than 100 species of spider in these habitats. In doing so, she was mainly in a region that has only been accessible to researchers since the end of civil war in Colombia in 2016. She discovered the new spider, which differs from related species in the striking structure of its reproductive organs, at altitudes of over 3,500 meters above sea-level. In the identification of this and many other spider specimens, Hopfe received valuable support from researchers at Universidad del Valle in Cali, Colombia, with which the University of Bayreuth has a research cooperation. Colombia has been identified as a priority country in the internationalization strategy of the University of Bayreuth, which is why it maintains close connections with several Colombian universities.The study of spiders from regions of such various huge climatic and ecological variety may also offer a chance to find answers to two as yet unexplored questions. It is not yet known whether temperatures, precipitation, or other climatic factors influence the evolution of spiders, or the properties of their silk. For example, is the proportion of species with extremely elastic silk in the lowland rainforest higher than in the semi-desert? And it is also still unclear whether the properties of the silk produced by a species of spider are modified by climatic factors. Would a spider living in the high mountains, such as Ocrepeira klamt, produce the same silk if it were native to a much lower region of the cordillera? The answer to these questions could provide important clues as to the conditions under which unusual spider silks develop.Along similar lines, it would also be interesting to explore whether there are spider silk proteins which, due to their properties, are even more suitable for certain applications in biomedicine and biotechnology than silk proteins currently known. "The greater the variety of spider silks whose structures and properties we know, the greater the potential to optimize existing biomaterials and to develop new types of biomaterials on the basis of silk proteins," Hopfe explains.Charlotte Hopfe's research was funded by the German Academic Exchange Service and the German Academic Scholarship Foundation.
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Animals
| 2,020 |
September 16, 2020
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https://www.sciencedaily.com/releases/2020/09/200916113515.htm
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Coconut rhinoceros beetle makes unexpected 'host shift' to Guam's cycad trees
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Researchers at the Western Pacific Tropical Research Center at the University of Guam have documented what biologists call a "host shift" of the coconut rhinoceros beetle in Guam. The beetle, first documented as an invasive species in Guam in 2007, has been devastating the island's ubiquitous coconut palms and is now also burrowing into Guam's endangered native cycad tree, Cycas micronesica. The results were published in June in Volume 13 of the
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The fact that coconut palms were the second most abundant tree on the island prior to the beetle's invasion was one factor that enabled the beetle's explosive population growth. The sustained efforts to develop an effective biological control program have not been effective, allowing the pest to establish a foothold throughout the island."Our initial alarm after documenting the CRB burrowing activity on cycad trees was the fact that Guam's cycad species was actually the most abundant tree on the island only 20 years ago," said Irene Terry, one of the authors of the study. "Where else have the most abundant and second most abundant forest species been threatened by the recent invasion of one non-native herbivore?"The authors used direct measurements of starch concentrations of the plant tissues to show that the island's heavily damaged coconut palms have declined in starch content so greatly that the host shift may have occurred in order to exploit the large doses of starch that are available in the cycad stems."The CRB behaviors that we documented fit the 'ecological fitting theory,' which states that shifting to a new host species is due to compatible resources or signals in the new host," said Terry, who has been studying the relationships among insect herbivores and the native cycad plant since 2005. This kind of host shift is opportunistic and may occur without any co-evolution processes.Prior to the beetle's host shift, the cycad population on Guam was already suffering from chronic damage by numerous non-native insect and mammal herbivores, resulting in 96% mortality of the cycad population in the past 15 years. The WPTRC cycad team's sustained research has revealed that the severity of damage by each herbivore species has exhibited an undulating pattern, with the most severe damage at any point in time changing from species to species."When the CRB damage in our managed gardens began showing up on several cycad species, we knew that it was only a matter of time before the CRB host shifts included Guam's native cycad," said Benjamin Deloso, who curates the University of Guam's interpretive cycad garden.The beetle's burrowing activity in managed gardens at the University of Guam also includes highly diverse cycad species that originate from Asia, Australia, Central America, and the Caribbean regions."The damaged species included two families and four genera, so the dietary needs of the coconut rhinoceros beetle appear to be met at the cycad Order level," Deloso said.The unexpected addition of the coconut rhinoceros beetle to the list of cycad herbivores reveals the need for continued observation of the cycad population by species experts so conservationists can best understand which of the threats are most in need of mitigation.The authors discussed the absence of international cycad experts from the contemporary conservation projects as a component of why the damage from the beetle was able to become established throughout the island without notice, and the continued absence of international experts from ongoing funded conservation projects will increase the probability of local extinction of the only native gymnosperm species in the region.
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Animals
| 2,020 |
September 16, 2020
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https://www.sciencedaily.com/releases/2020/09/200916090532.htm
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Paleontology: The oldest known sperm cells
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An international team of paleontologists has discovered giant sperm cells in a 100-million year-old female ostracod preserved in a sample of amber. Clearly, the tiny crustacean had mated shortly before being entombed in a drop of tree resin.
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In another fascinating snapshot from deep time, an international team of paleontologists has reported the discovery of specimens of a minuscule crustacean that dates back to the Cretaceous (about 100 million years ago), conserved in samples of amber from Myanmar. The most spectacular find is a single female, which turns out on closer examination to contain giant sperm cells in its reproductive tract. In fact, this is the oldest fossil in which sperm cells have been conclusively identified. Moreover, the specimen represents a previously unknown species of crustacean, which has been named Myanmarcypris hui. M. hui was an ostracod, as clearly indicated by the paired calcareous valves that form the carapace, whose form recalls that of a mussel shell. Ostracods have been around for 500 million years, and thousands of modern species have been described. They are found in the oceans and in freshwater lakes and rivers. Fossilized shells of these crustaceans are by no means rare, but the specimens preserved in Burmese amber reveal details of their internal organs, including those involved in reproduction. "The finds gave us an extremely rare opportunity to learn more about the evolution of these organs," says Ludwig-Maximilians-Universitaet (LMU) in Munich geobiologist Renate Matzke-Karasz, who played a major role in the morphological analysis of the fossils.During the Cretaceous period, ostracods must have lived in the coastal and inland waters of what is now Myanmar, which were fringed by forests dominated by trees that produced huge quantities of resin. The newly described specimens are among the many organisms that were trapped in the oozing blobs of the gooey substance. In recent years, the amber found in the province of Kachin has yielded a spectacular trove of fossils, including frogs and snakes, as well as part of a putative dinosaur (according to new evidence, that specimen may actually represent an unusual lizard). Over the past 5 years, hundreds of previously unknown species have been described based on these inclusions. Indeed, many of them have forced evolutionary biologists to reconsider conventional hypotheses concerning phylogenetic and ecological relationships.The new ostracod specimens were analyzed with the aid of computer-assisted 3D X-ray reconstructions. The images revealed astonishing details of the anatomy of these animals, ranging from their tiny limbs to their reproductive organs. -- And in one female specimen, Matzke-Karasz and her colleagues discovered ripe sperm. The cells were discovered in the paired sperm receptacles in which they were stored after copulation, ready for release when the female's eggs matured. "This female must have mated shortly before being encased in the resin," says He Wang of the Chinese Academy of Sciences in Nanjing. The X-ray images also revealed the sperm pumps and the pair of penises that male ostracods insert into the twin gonopores of the females.The finds in Burmese amber provide unprecedented insights into an unexpectedly ancient and advanced instance of evolutionary specialization. "The complexity of the reproductive system in these specimens raises the question of whether the investment in giant sperm cells might represent an evolutionarily stable strategy, says Matzke-Karasz. The males of most animal species (including humans) produce very large numbers of very small sperm. Comparatively few animals, including some fruit flies -- and of course, ostracods -- have opted for a different approach. They make a relatively small numbers of oversized sperm, whose motile tails are several times longer than the animal itself."In order to prove that the use of giant sperm is not an extravagant whim on the part of evolution, but a viable strategy that can confer an enduring advantage that enables species to survive for long periods of time, we must establish when this mode of reproduction first appeared," says Matzke-Karasz. Examples of fossilized sperm cells are extremely rare. The oldest known ostracod sperm (prior to the new discovery) are 17 million years old, and the previous record age, 50 Myr, was held by a species of worm. The new evidence extends that age by a factor of at least two. The fact that animals had already developed giant sperm 100 million years ago implies that this reproductive strategy can indeed be successful in the (very) long term, Matzke-Karasz points out. "That's a pretty impressive record for a trait that requires a considerable investment from both the males and females of the species. From an evolutionary point of view, sexual reproduction with the aid of giant sperm must therefore be a thoroughly profitable strategy."
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Animals
| 2,020 |
September 15, 2020
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https://www.sciencedaily.com/releases/2020/09/200915121318.htm
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Chimpanzees show greater behavioral and cultural diversity in more variable environments
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Behavioural flexibility enables species to adapt to uncertainty and changing ecological conditions via mechanisms such as innovation and greater cognitive capacity. Indeed, large brained species of birds or nonhuman primates often live in habitats that are highly seasonal and can sustain periodic resource shortages. Similarly, our own species is thought to have evolved an unprecedented level of behavioural flexibility in order to adapt and survive in fluctuating and unpredictable environmental conditions.
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One of our closest living relatives, chimpanzees, possess a number of diverse behaviours observed across a variety of contexts, that are found in some wild populations while being absent in others. These include tool use for communication, foraging on insects, algae, nuts, or honey, and thermoregulatory behaviours such as bathing in pools or using caves in extremely hot environments. Importantly, some of these behaviours also show evidence for being socially learned and are therefore considered to be cultural traditions particular to certain chimpanzee groups. This degree of behavioural variation provides a unique opportunity to investigate the effects of environmental conditions on both behavioural and cultural diversity within a single species.An international team of researchers led by Ammie Kalan and Hjalmar Kühl of the Pan African Programme: the Cultured Chimpanzee (PanAf) at the Max Planck Institute for Evolutionary Anthropology compiled a data set combining fieldwork conducted by the PanAf at 46 field sites, plus an in-depth literature search on chimpanzee research. For 144 chimpanzee social groups they investigated the long-standing question of under which environmental conditions chimpanzees acquire more behavioural traits. They used their unique dataset to test whether chimpanzee groups were more likely to possess a larger set of behaviours if they lived in more seasonal habitats or habitats where forest cover repeatedly changed over the last thousands of years. The behaviours largely included tool use and more than half have been described as cultural in previous studies.The authors found that both recent and historical sources of environmental variability were positively associated with chimpanzee behavioural and cultural diversity. "Chimpanzees experiencing greater seasonality, living in savannah woodland habitats and located further away from historical Pleistocene forest refugia were more likely to have a larger set of behaviours present," describes Kalan. These results suggest that a species closely related to humans also uses behavioural flexibility to adapt to more seasonal and unpredictable environments. "Since the behaviours we examined are largely considered cultural, we could further infer that environmental variability also supports cultural diversification in chimpanzees," says Kalan.With respect to human evolution, behaviour is often difficult to study via the fossil record alone, therefore studies of nonhuman primates such as this one can provide us a comparative insight into the potential selection pressures that may have been significant in our own past. "Many studies suggest that environmental variation acts as an important driver for behavioural or cultural diversification in both humans and animals, but this is some of the first cross-population data within a single species to support this idea," says Kalan.The study has also demonstrated the great potential of a cross-population research approach and it is very likely that it will continue to provide fascinating insights into the emergence of chimpanzee population diversity. "While we have learned a lot about the relationship between environmental variability and chimpanzee behavioral diversity in this study, there may be other demographic and social factors that have also played an important role in the process of behavioral diversification," says Kühl, a researcher at the Max Planck Institute for Evolutionary Anthropology and the German Centre for Integrative Biodiversity Research (iDiv). "With continued efforts to study and compare chimpanzee populations at large numbers, I am convinced that many more exciting discoveries will be made in the future that will provide further insights into the mechanisms of behavioral diversification in chimpanzees, but that will help us to also better understand our own evolutionary history."The PanAf continues to collect species and behavioural annotations from their video camera traps via Chimp&See. At this platform anyone can watch the PanAf videos from across the chimpanzee range, and by classifying the species and behaviours they observe, contribute to the growing PanAf data set.
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Animals
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September 14, 2020
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https://www.sciencedaily.com/releases/2020/09/200914172925.htm
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Human activities promote disease-spreading mosquitoes; more study needed for prevention
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Disease-spreading mosquitoes may be more likely to occupy areas impacted by human activities like pesticide use and habitat destruction, than they are areas less disturbed by humans, a recent Oregon State University study found.
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Working in a national park in South Africa, researchers found a significant difference in the abundance and species composition of mosquitoes inside the park versus densely populated areas outside the park, with the species known to spread diseases such as malaria and Zika virus more common in the human-impacted areas outside the park."People care a lot about what environment a lion needs to succeed in; we've researched that extensively. But people don't do that with mosquitoes. We don't understand them as a group of species and how their ecology differs between species," said study co-author Dr. Brianna Beechler, a disease ecologist and assistant professor of research in Oregon State University's Carlson College of Veterinary Medicine.To find disease mitigation strategies for vector-borne diseases, which are diseases that spread via parasites like mosquitoes and ticks, mosquitoes are an obvious target, Beechler said. But scientists don't yet understand mosquitoes well enough to specifically target the species that cause disease."All we can do is reduce mosquitoes overall, but what may be more effective is to reduce certain species by modifying their habitats," she said.To compare how mosquitoes fared inside Kruger National Park versus in densely populated areas, researchers looked at five "pressures" wrought by human presence: organophosphate pesticide abundance; eutrophication, which is the over-mineralization of water that leads to widespread algae growth; population density; ungulate biomass, which includes domestic animals like cattle and wild animals like impala and buffalo; and vegetation loss.Human populations affect mosquito habitat and breeding patterns in a sort of domino effect. For example, pesticide use spreads into ponds and other small bodies of water, killing the fish and removing the natural predators that would otherwise eat mosquito larvae and keep the insect population low.During South Africa's wet season in 2016-17, researchers trapped 3,918 female mosquitoes from 39 different species both inside and outside the national park.Mosquito abundance was nearly three times higher outside the park -- in areas dominated by humans -- than inside the park. And there was a significant difference in the species composition of mosquitoes, with the species known to spread diseases (like dengue, West Nile virus, chikungunya, yellow fever and Zika virus) more common outside the park than inside."It seems to suggest that disease-carrying mosquito species certainly did better in human-altered environments," Beechler said, though she noted it's hard to ascertain at this stage why that is. More study is needed to understand the ecological requirements of different mosquito species.There are some success stories with current mosquito mitigation strategies. Beechler cited a technique in the Caribbean where residents are encouraged to introduce fish into any standing water in their vicinity, so the fish can eat mosquito larvae before they have time to hatch. And several countries have experimented with releasing clusters of sterile mosquitoes into the wild, so they will eat and take up resources but are not able to reproduce."But none of those are targeted at disease-transmitting mosquitoes versus non-disease-transmitting mosquitoes," she said. "It's just, 'All mosquitoes are created equal.'"Vector-borne disease is not currently a pressing issue in Oregon, though there are several different species of mosquito in the state and some have been known to spread West Nile virus. However, mosquitoes carrying malaria, Zika and chikungunya have all been pushing into new territory in recent years."With climate change, mosquito distributions are likely to change, and disease distributions are likely to change," Beechler said. "So it'd be nice to know how to target those species before that happens."
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Animals
| 2,020 |
September 14, 2020
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https://www.sciencedaily.com/releases/2020/09/200914165541.htm
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New rules for algae species classification
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FSU Assistant Professor of Biological Science Sophie McCoy and her team are proposing formal definitions for algae species and subcategories for the research community to consider: They are recommending algae be classified first by DNA and then by other traits.
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The work, which includes collaborations with Stacy Krueger-Hadfield, assistant professor of biology at the University of Alabama at Birmingham, and Nova Mieszkowska, a research fellow at the Marine Biological Association in the United Kingdom, was published this week in the "Algal species should evolve separately from other lineages, so that's DNA-based, but we should also take into account differences in their ecology, such as what they look like or their role in the environment," McCoy said.The article was published as a perspective rather than offering definitive answers, and the team hopes the larger scientific community will comment on it and start an important conversation.Algae matter more than most people realize because the organisms make about half of the oxygen in the world, McCoy said. Humanity depends on algae, as does the entire food web of the ocean.Scientists have established ways to define animal species, such as determining an organism's ability to produce viable offspring that can subsequently reproduce. For instance, a horse and a donkey can create a mule, but a mule cannot reproduce. That helps classify horses and donkeys as separate species. But that type of categorization doesn't work well for algae because it has unique and complex life stages and very often interbreeds with other algal species."Rather than having a 'species tree,' like a family tree, algae have more of a web," McCoy said.That intricacy has made it difficult to formalize categories to classify algae species. Some scientists might classify offspring of two algal species as a distinct new species while others would not. Or some might classify algae species by discrete DNA while others classify by physical characteristics."We aren't all using the same rules, so are we actually looking at different breeds or populations and then artificially calling them species?" McCoy said. "Depending on how we apply these rules, the number of species could go way up or way down."The International Union for Conservation of Nature Red List of Threatened Species is the world's most comprehensive inventory of the global conservation status of biological species. The IUCN red list helps scientists evaluate a species' extinction risk. So, how a species is defined changes the perception of biodiversity and conservation, she said.Beyond conservation, catastrophes -- from algal blooms in waterways to the destruction of coral reefs -- could be mitigated by discussing and clarifying algal species classification. McCoy said some of the mysteries surrounding this type of growth are likely related to a lack of uniform identification."If we are mistakenly separating or grouping species, we're just not going to understand how different types of algae are responding to pollution or climate change," she said.This philosophical change in what it means to be a species is a starting point for McCoy and the team. In addition to starting a conversation, she plans to conduct research that builds on the concept over the next year.
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Animals
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September 14, 2020
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https://www.sciencedaily.com/releases/2020/09/200914112224.htm
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Animals' magnetic 'sixth' sense may come from bacteria
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A University of Central Florida researcher is co-author of a new paper that may help answer why some animals have a magnetic "sixth" sense, such as sea turtles' ability to return to the beach where they were born.
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The question is one that has been unresolved despite 50 years of research."The search for a mechanism has been proposed as one of the last major frontiers in sensory biology and described as if we are 'searching for a needle in a hay stack,'" says Robert Fitak, an assistant professor in UCF's Department of Biology, part of UCF's College of Sciences.Fitak and researchers in the United Kingdom and Israel recently authored an article in Magnetotactic bacteria are a special type of bacteria whose movement is influenced by magnetic fields, including the Earth's.Animals that sense Earth's magnetic field include sea turtles, birds, fish and lobsters. Sea turtles, for example, can use the ability for navigation to return to the beach where they were born.Learning how organisms interact with magnetic fields can improve humans' understanding of how to use Earth's magnetic fields for their own navigation purposes. It can also inform ecological research into the effects of human modifications of the magnetic environment, such as constructing power lines, on biodiversity. Research into the interaction of animals with magnetic fields can also aid the development of therapies that use magnetism for drug delivery.In the article, the researchers review the arguments for and against the hypothesis, present evidence published in support that has arisen in the past few years, as well as offer new supportive evidence of their own.Their new evidence comes from Fitak, who mined one of the largest genetic databases of microbes, known as the Metagenomic Rapid Annotations using Subsystems Technology database, for the presence of magnetotactic bacteria that had been found in animal samples.Previous microbial diversity studies have often focused on large patterns of the presence or absence of bacteria phyla in animals rather than specific species, Fitak says."The presence of these magnetotactic bacteria had been largely overlooked, or 'lost in the mud' amongst the massive scale of these datasets," he says.Fitak found, for the first time, that magnetotactic bacteria are associated with many animals, including a penguin species, loggerhead sea turtles, bats and Atlantic right whales.For instance, Candidatus Magnetobacterium bavaricum regularly occurred in penguins and loggerhead sea turtles, while Magnetospirillum and Magnetococcus regularly occurred in the mammal species brown bats and Atlantic right whales.Fitak says researchers still don't know where in the animal that the magnetotactic bacteria would live, but it could be that they would be associated with nervous tissue, like the eye or brain."I'm working with the co-authors and local UCF researchers to develop a genetic test for these bacteria, and we plan to subsequently screen various animals and specific tissues, such as in sea turtles, fish, spiny lobsters and birds," Fitak says.Before joining UCF in 2019, Fitak worked for more than four years as a postdoctoral researcher at Duke University performing experiments to identify genes related to a magnetic sense in fish and lobsters using modern genomic techniques.He says the hypothesis that animals use magnetic bacteria in a symbiotic way to gain a magnetic sense warrants further exploration but still needs more evidence before anything conclusive can be stated.
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Animals
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September 14, 2020
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https://www.sciencedaily.com/releases/2020/09/200914112205.htm
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DNA unlocks a new understanding of coral
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Scientists have developed a new genetic tool that can help them better understand and ultimately work to save coral reefs.
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"Surprisingly, we still don't know how many coral species live on the Great Barrier Reef, how to identify them, or which species live where. And those are the first steps in saving an ecosystem like that," said Dr Peter Cowman from the ARC Centre of Excellence at James Cook University (Coral CoE at JCU).Dr Cowman led an international study on coral classification. Classification explains how species are related to each other. Shared similarities and differences provide a key to help identify species. For example, dogs and cats are classified on different branches of the evolutionary tree using their body design.A seemingly finer detail, like how cats can retract their claws and dogs cannot, helps people decide whether a newly discovered species of small carnivore is more like a dog or a cat.Dr Cowman said an important challenge when identifying corals is that the same species can grow in many different ways."For instance, some species can grow with either a plate or branch structure. The study found classifying corals by their physical characteristics didn't match the classifications based on their genetics," he said.Species identification underpins almost all biological and ecological research, and the new study challenges more than 200 years of coral classification. The researchers say the 'traditional' method does not accurately capture the differences between species or their evolutionary relationships.Co-author Professor Andrew Baird, also from Coral CoE at JCU, led a recent scientific journey along the Great Barrier Reef, uncovering 'treasure troves' of new, unidentified coral species."The traditional classification of corals is dead," Prof Baird said."But these new molecular tools allow us to reinvent a new classification system on the ashes of the old. Hence, the name we have given to the research: Project Phoenix," he said."These are exciting times to be a coral taxonomist.""We need to review the way we currently identify corals," said co-author Dr Tom Bridge from Coral CoE at JCU, who is also the curator of corals at the Queensland Museum.Dr Bridge said research in the past ten to 20 years has already revolutionised the understanding of the older branches on the evolutionary tree of corals. But, to date, there has been little progress on the more recent twigs of the 'tree' -- the living species -- particularly with the most diverse and ecologically-important group: the Acropora."The Acropora are the branching 'staghorn' corals that dominate reefs," Dr Bridge said. "Yet, even in well-researched locations like the Great Barrier Reef, we can't identify many of these species accurately."Dr Cowman said the traditional method doesn't reflect the tens of millions of years of coral evolution."At the moment, we're flying blind," he said.Dr Andrea Quattrini, curator of corals at the Smithsonian Institution's National Museum of Natural History, developed the new genetic tool. She said it provides a way forward with plans to secure the future of coral reefs."By comparing thousands of key genetic coral features, we were able to discern the evolutionary relationships of corals from the Great Barrier Reef and broader Indo-Pacific region," Dr Quattrini said."The result is a new classification that provides important scientific knowledge to assess the various intervention strategies currently being proposed on the Great Barrier Reef and elsewhere."Some of the interventions being proposed on the reef include hybridising species and moving some populations south."It's clear we do not know enough about many of the species we're dealing with. This new method can help generate the robust science we need to assess such proposals," Dr Bridge said.
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Animals
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September 14, 2020
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https://www.sciencedaily.com/releases/2020/09/200914095852.htm
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Wildlife trade threats: The importance of genetic data in saving an endangered species
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In Southeast Asia, wildlife trade is running rampant, and Vietnam plays a key role in combating wildlife trafficking.
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Since the country opened its market to China in the late 1980s, a huge amount of wildlife and its products has been transported across the border every year. Species have also been exported to other Asian countries, Europe and the USA. Furthermore, in recent years, Vietnam has also supported the transit of pangolin scales and other wildlife products from across Asia and even as far as Africa all the way to China and other destinations.Additionally, in line with the expanding wealthy middle class, consumption of wildlife and its products has risen dramatically in Vietnam. As a consequence, the country takes on all three major roles in the international wildlife trade: export, transit and consumption.Freshwater turtles and tortoises make up a large part of the international trade between Vietnam and China and the domestic trade within Vietnam. Meanwhile, due to the increasing use of social networks, wildlife trade is shifting to online-based platforms, thereby further facilitating access to threatened species. Consequently, the Vietnamese pond turtle and the Swinhoe's softshell turtle, for example, are already on the brink of extinction. Despite the repeated recent survey efforts of conservation biologists, no viable populations of their species have been found.One of the effective approaches to the conservation of the most endangered species is to have confiscated animals released back into the wild, following the necessary treatment and quarantine, or transferring them to conservation breeding programmes. However, in either of the cases, it is necessary to know about the origin of the animals, because the release of individuals at sites they are not naturally adapted to, or at localities inhabited by populations of incompatible genetic makeup can have negative effects both on the gene pool and ecosystem health.In the present research article, published in the peer-reviewed open-access scientific journal Having analysed field-collected and local trade samples along with confiscated animals, the researchers concluded that there is a significant number of genetically distinct lineages distributed in Vietnam and China, and that local trade samples could provide key data for resolving the genetic patterns of the species. They remind that Four-eyed turtles are getting more and more difficult to find in the wild.On the other hand, the study highlights that confiscated animals are of various origin and, therefore, must not be released arbitrarily where they have been seized. Instead, the researchers recommend that captive programmes establish regular genetic screenings to determine the origin of confiscated turtles, so that the risk of crossing different lineages is eliminated. Such genetic screenings are of crucial importance to solve the current issues with biodiversity conservation in the country and the region."Like other developing countries, Vietnam does not have any specific guidelines on how to release confiscated animals back into the wild yet. This and other similar studies emphasise the role of the government in the implementation of stricter laws and regulation," said Dr. Minh D. Le, lead author of the study."This research once more underscores the IUCN's One Plan Approach, which aims to develop integrative strategies to combine in situ and ex situ measures with expert groups, for the purposes of species conservation," added Dr. Thomas Ziegler of the Cologne Zoo.
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Animals
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September 10, 2020
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https://www.sciencedaily.com/releases/2020/09/200910110836.htm
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The surprising rhythms of Leopards: Females are early birds, males are nocturnal
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Tanzania's Udzungwa Mountains are carpeted by dense rainforest, making the area impossible to reach by jeep or other vehicles. As such, the leopards in this area have never been subject to the prying eyes of researchers. Until now.
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After covering 2,500 square kilometers on foot, setting up 164 game camera traps and collecting more than 5000 days worth of footage from the area, the Natural History Museum of Denmark's Rasmus W. Havmøller has discovered new and surprising knowledge about these spotted predators."I'm the first person to study leopards in this area, simply because it is so inaccessible. It took several pairs of good hiking boots, let me put it that way," says Havmøller, who never actually got to see one of the shy leopards with his own eyes. Instead, he had to "settle" for buffalo and elephants.While Havmøller never caught a glimpse of a leopard himself, his 164 camera traps most certainly did. Using motion sensors, the cameras captured the leopards, as well as forest antelopes, baboons and other leopard prey on film. Camera observations revealed leopard behaviour that contradicts previous assumptions."In the past, leopards were thought to be most active at dusk. Very surprisingly, the study shows that leopards hunt and move around at very different times of the day depending on whether they are females or males," says Rasmus W. Havmøller, who adds:"Females are typically active from early through late morning, and then a bit before sunset, while males only really wake up at night."This is the first time that differences in activity patterns between male and female leopards have been studied.Differences between male and female leopards have only recently begun to be studied, so there is still much to learn about the animal. But researchers need to hurry. Rapidly growing human populations in Africa and India are the greatest threat to these animals, which are forced from their habitats and shot when they near livestock."Globally, things are going awfully for leopards, with sharp declines in their populations over the past 100 years. Furthermore, these animals aren't monitored all that well. In part, this is because it is difficult. But also, because there has been a greater focus on species that are even more endangered, including lions, tigers and cheetahs. Therefore, it might be that the leopards in Udzungwa present the last chance to study these creatures in a diversified environment, one that has only been lightly impacted by humans, before they end up becoming highly endangered" explains Rasmus W. Havmøller.The researcher believes that the results will provide a better understanding of the lives of wild leopards -- an understanding that may help prevent their complete extinction."The fact that female leopards are active well into the morning makes them more vulnerable to human activities, since this is when we as humans are most active. To protect something, one needs to have some knowledge about it. During my study, we also discovered that a leopard from the rainforest doesn't move into semi-arid areas or onto the savannah, or vice versa. It's very strange. Why they don't is the next big question," concludes Havmøller.
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Animals
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September 10, 2020
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https://www.sciencedaily.com/releases/2020/09/200910090110.htm
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Thousands of species recorded in a speck of soil
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Researchers at McMaster University have developed a new technique to tease ancient DNA from soil, pulling the genomes of hundreds of animals and thousands of plants -- many of them long extinct -- from less than a gram of sediment.
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The DNA extraction method, outlined in the journal The researchers analyzed permafrost samples from four sites in the Yukon, each representing different points in the Pleistocene-Halocene transition, which occurred approximately 11,000 years ago.This transition featured the extinction of a large number of animal species such as mammoths, mastodons and ground sloths, and the new process has yielded some surprising new information about the way events unfolded, say the researchers. They suggest, for example, that the woolly mammoth survived far longer than originally believed.In the Yukon samples, they found the genetic remnants of a vast array of animals, including mammoths, horses, bison, reindeer and thousands of varieties of plants, all from as little as 0.2 grams of sediment.The scientists determined that woolly mammoths and horses were likely still present in the Yukon's Klondike region as recently as 9,700 years ago, thousands of years later than previous research using fossilized remains had suggested."That a few grams of soil contains the DNA of giant extinct animals and plants from another time and place, enables a new kind of detective work to uncover our frozen past," says evolutionary geneticist Hendrik Poinar, a lead author on the paper and director of the McMaster Ancient DNA Centre. "This research allows us to maximize DNA retention and fine-tune our understanding of change through time, which includes climate events and human migration patterns, without preserved remains."The technique resolves a longstanding problem for scientists, who must separate DNA from other substances mixed in with sediment. The process has typically required harsh treatments that actually destroyed much of the usable DNA they were looking for. But by using the new combination of extraction strategies, the McMaster researchers have demonstrated it is possible to preserve much more DNA than ever."All of the DNA from those animals and plants is bound up in a tiny speck of dirt," explains Tyler Murchie, a PhD candidate in the Department of Anthropology and a lead author of the study."Organisms are constantly shedding cells throughout their lives. Humans, for example, shed some half a billion skin cells every day. Much of this genetic material is quickly degraded, but some small fraction is safeguarded for millenia through sedimentary mineral-binding and is out there waiting for us to recover and study it. Now, we can conduct some remarkable research by recovering an immense diversity of environmental DNA from very small amounts of sediment, and in the total absence of any surviving biological tissues."
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Animals
| 2,020 |
September 10, 2020
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https://www.sciencedaily.com/releases/2020/09/200910090034.htm
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Baboon matriarchs enjoy less stress
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You know the type: Loud. Swaggering. Pushy. The alpha male clearly runs the show. Female alphas are often less conspicuous than their puffed up male counterparts, but holding the top spot still has its perks.
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Wearing the crown means privileged access, like never having to wait your turn. And now, a study of female baboons points to another upside to being No. 1: less stress.In a Duke University-led study, researchers describe how, after 18 years of collecting fecal samples from 237 female baboons in Amboseli National Park in Kenya, they found that alpha females have significantly lower levels of glucocorticoids, hormones produced in response to stress.Baboon females are a very orderly group, with one reigning alpha who gets her way over everyone else, a second-in-command who dominates all but the alpha, and so on down to the bottom-ranked female, who gets pushed around by most everyone.Dominance gives baboons a lot of advantages in life. Higher-ranking females get preferential treatment in grooming bouts and first dibs at feeding time. As a result, their babies grow faster and are more likely to survive to adulthood.Considering all these perks, the researchers say it came as no surprise that higher status means lower glucocorticoids. They found that the larger a female's share of subordinates, the lower her glucocorticoid levels.But what puzzled the team was why the top-ranking females stood out so much from the rest. Their stress hormone levels were 8% lower than everyone else in their group.The findings were surprising because baboons aren't like some other species with clear-cut "queens," said first author Emily Levy, a biology Ph.D. student in Susan Alberts' lab at Duke.Top-ranking baboon females don't claim exclusive rights to reproduction, as in some other species."You don't usually look at an alpha female baboon and see a bully," Levy said.The researchers aren't sure what drives the disparity between leaders and non-leaders in baboon females, but suggest two possible explanations.It could be that alpha females experience less stress because they hold their position longer than other females, Levy said.A baboon matriarch rules in a society in which power is handed down from mother to daughter. All but the top-ranking female eventually cede their spot to their daughters as they get older. But once ensconced in power, alphas have been known to rule for eight years or more.Take Pindua, an alpha female who ruled unchallenged until she died in 1989. Only then did her daughter assume the throne, recalls Alberts, who has spent 30 years studying wild baboons as part of the Amboseli Baboon Research Project."She was definitely a Grand Dame -- very calm and non-reactive, but unambiguous about her power," Alberts said.There's another reason why the alpha female may be different from the others on measures of stress hormones, Alberts said. It's that there's no female above her to push her around.The alpha female only has herself to answer to, Alberts said. She goes where she pleases. "Nobody's going to mess with her."Previous research by Alberts and colleagues at Princeton University found the opposite pattern for alpha male baboons. Top-ranked males have the highest levels of stress hormones, presumably because instead of inheriting their status, as females do, males have to fight to stay on top."In male baboons you can just watch the alpha for a day and say, wow, that individual is kicking everybody's butt," Levy said. "For females it's a little more nuanced."
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Animals
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September 9, 2020
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https://www.sciencedaily.com/releases/2020/09/200909124012.htm
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National parks preserve more than species
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National parks are safe havens for endangered and threatened species, but an analysis by Rice University data scientists finds parks and protected areas can preserve more than species.
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In a study published online this week in the journal In wildlife conservation, diversity often refers to the variety of species in an ecosystem. But ecologists also study functional diversity, the abundance and variation of traits like body size, diet and reproductive rate. Trait diversity can be measured independent of species diversity and provide additional insight about the overall health of an ecosystem.In the study, Gorczynski and Beaudrot analyzed more than 4,200 photos of mammals taken in the park between 2007 and 2014 and found the diversity of mammal traits within the park did not decline, despite deforestation that fragmented the forests on more than half of the surrounding private lands."It is a bit of a surprise," said Gorczynski, a Ph.D. student in Rice's Department of Biosciences. "Previous studies in other places have shown that trait diversity is more sensitive to human disturbance than species diversity. Trait diversity can decline more quickly than species diversity, both in cases where species go extinct and where they don't."There were no mammal extinctions in Braulio Carrillo during the eight years of the study, and Beaudrot, an assistant professor of biosciences at Rice, said the trait analysis revealed a level of functional redundancy that could allow the park's ecosystem to continue functioning even if some of its mammals go extinct in the future."It's well-established that national parks preserve species, and our results show national parks can be more resilient than expected, at least over the time period we examined," she said.Beaudrot said the results are encouraging, but she said it would be a mistake to assume that all national parks are as resilient as Braulio Carrillo."This shows what's possible, but the situation could be very different at other parks or over longer time periods," she said. "We need comparable studies for other parks, other protected areas and nonprotected areas."This is an area where data science can make a difference," she said. "Some of the data needed to make those comparisons are already available."
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Animals
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September 9, 2020
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https://www.sciencedaily.com/releases/2020/09/200909114823.htm
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More cats might be COVID-19 positive than first believed, study suggests
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A newly published study looking at cats in Wuhan, where the first known outbreak of COVID-19 began, shows more cats might be contracting the disease than first believed.
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Researchers from Huazhong Agricultural University, in the Chinese city, took blood samples from 102 cats between January and March 2020, following the first outbreak. Nasal and anal swabs were also collected.Reporting their findings in peer-reviewed journal None of the cats actually tested positive for COVID-19 or displayed obvious symptoms and, according to the results of return visits, none of these felines have died.The sample of cats looked at included 46 abandoned from 3 animal shelters, 41 from 5 pet hospitals, and 15 cats were from COVID-19 patient families.The three cats with the highest levels of antibodies were all owned by patients who had been diagnosed with COVID-19, whilst there were also signs of cats being infected with the virus by other cats from those that were abandoned (4) or based in the pet hospitals (4).Commenting on the findings, lead author Meilin Jin states that whilst there is currently no evidence for cat-to-human transmission, precautions should be considered."Although the infection in stray cats could not be fully understood, it is reasonable to speculate that these infections are probably due to the contact with SARS-CoV-2 polluted environment, or COVID-19 patients who fed the cats."Therefore measures should be considered to maintain a suitable distance between COVID-19 patients and companion animals such as cats and dogs, and hygiene and quarantine measures should also be established for those high-risk animals."The team assessed the type of antibody reactions in thorough detail and were able to describe the dynamic characteristics of the antibodies found.Amongst many discoveries within the antibodies, they saw that the type of reaction produced by the cats resembles those observed in seasonal coronavirus infections, implying that the cats who have had SARS-CoV-2 infection "remain at risk of re-infection."The authors state that this is a similar transient antibody response to also be observed in humans, and that their study should be used going forwards as a "reference for the clinical treatment and prevention of COVID-19.""We suggest that cats have a great potential as an animal model for assessing the characteristic of antibody against SARS-CoV-2 in humans," they add.From here, the team state that more research is needed to establish the route of Covid-19 from humans to cats."Retrospective investigation confirmed that all of antibody positive samples were taken after the outbreak, suggesting that the infection of cats could be due to the virus transmission from humans to cats. Certainly, it is still needed to be verified via investigating the SARS-CoV-2 infections before this outbreak in a wide range of sampling," Jin states.
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Animals
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September 9, 2020
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https://www.sciencedaily.com/releases/2020/09/200909114801.htm
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Bat tick found for the first time in New Jersey
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A tick species associated with bats has been reported for the first time in New Jersey and could pose health risks to people, pets and livestock, according to a Rutgers-led study in the
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This species ("All ticks feed on blood and may transmit pathogens (disease-causing microbes) during feeding," said lead author James L. Occi, a doctoral student in the Rutgers Center for Vector Biology at Rutgers University-New Brunswick. "We need to be aware that if you remove bats from your belfry, attic or elsewhere indoors, ticks that fed on those bats may stay behind and come looking for a new source of blood. There are records of This soft tick species, a parasite of bats, is known to be in 29 of the 48 contiguous U.S. states, and was confirmed in New Jersey as larvae collected from big brown bats (While the public health risk remains unknown, "finding them on New Jersey bats was an unusual event that prompted bat specialists to contact us. Maybe these ticks are becoming more common," said senior author Dina M. Fonseca, a professor and director of the Center for Vector Biology in the Department of Entomology in the School of Environmental and Biological Sciences.In other states, "This tick belongs to the family Scientists in the Endangered and Nongame Species Program of the Division of Fish and Wildlife in the New Jersey Department of Environmental Protection found the tick larvae on bats last year. Technically, this is not the first time a soft tick has been reported in New Jersey. In 2001, a related tick species -- "The next steps are to collect more soft tick specimens and test them for disease-causing microbes," Occi said.Rutgers coauthors include Andrea M. Egizi, a visiting professor in the Department of Entomology and a research scientist with the Monmouth County Tick-borne Diseases Laboratory hosted by the Rutgers Center for Vector Biology. Scientists at the New Jersey Division of Fish and Wildlife, Smithsonian Institution and Walter Reed Army Institute of Research contributed to the study.
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Animals
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September 8, 2020
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https://www.sciencedaily.com/releases/2020/09/200908131127.htm
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Lost frogs rediscovered with environmental DNA
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Scientists have detected signs of a frog listed extinct and not seen since 1968, using an innovative technique to locate declining and missing species in two regions of Brazil.
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The frog, The eDNA technique offers a way to survey that can confirm the presence of species undetected by traditional methods, providing a tool for conservation scientists to evaluate the presence of threatened species, especially those with low population densities and those not seen in years.After careful research to identify species at various levels of threat in these regions of Brazil, the researchers used the eDNA method to search for 30 target amphibian species in six localities where the frogs were known to previously live."Little bits of DNA in the environment don't tell us about how many individuals there are or whether those individuals are healthy, but it does tell us that the species is still present," said senior author Kelly Zamudio, the Goldwin Smith Professor of Ecology and Evolutionary Biology in the College of Arts and Sciences."This is one more kind of survey data, and for species that are declining or locally disappeared, it not only means they are there, but there's now the potential to study them in more detail," she said, noting that for many species, very little is known.Around the world, conservationists have been challenged to keep pace with declining and disappearing amphibians. At the same time, living organisms leave DNA traces in the soil, water and air. Now, scientists are increasingly using highly sensitive sampling techniques to detect eDNA for conservation purposes.In the study, the researchers targeted 13 frog species that have totally disappeared and are presumed extinct; 12 frogs that have disappeared locally but are still found in other parts of their range; and five species that were once very abundant and are still there but hard to find.The researchers hiked into the sampling sites carrying battery packs, a shoebox-sized peristaltic pump and backpacks of sterile tubing. They used the pump and tubing to draw up to 60 liters of stream or pond water through a capsule fitted with a filter for capturing DNA. A buffer was then applied to stabilize and preserve the DNA on the filter.Back in the lab, the researchers extracted the DNA, genetically sequenced it, weeded out genetic material from humans, pigs, chickens and other organisms until they could isolate all the frog DNA."Now you've got a subset of genetic sequences that we know only belong to frogs, and then it's step by step, going finer and finer, until you get to the genus and species you are looking for," Zamudio said.Identifying "We know there's a Megaelosia there," Zamudio said, "we just don't know which one it is, but the only one that has ever been reported there historically is the one that went missing. Do we believe it? That's how far the analysis can take us."Zamudio added that samples from nearby areas may be worth collecting for more signs of Carla Martins Lopes, a researcher at São Paulo State University in Brazil, is the paper's first author.The Brazilian National Council for Scientific and Technological Development and the São Paulo Research Foundation funded the study.
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Animals
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September 8, 2020
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https://www.sciencedaily.com/releases/2020/09/200908131034.htm
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Engineering speciation events in insects may be used to control harmful pests
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Species typically evolve over the course of eons, but researchers at the University of Minnesota have developed a way to do it in less than a year. A team of scientists led by Mike Smanski, Ph.D., in the College of Biological Sciences (CBS) has generated speciation events in fruit flies so that engineered strains can reproduce normally with each other, but mating with unmodified flies results in non-viable offspring.
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This research, published in "Speciation is a fundamental process that drives how life evolves on this planet. Gaining engineering control over speciation will impact our ability to control pests that spread disease, harm crops or degrade the environment," said Smanski, a study author and professor in CBS. "This is one of several new approaches to pest control using modern genome-editing tools to essentially convert the pest organism into the pesticide. Any time our engineered flies attempt to reproduce with wild flies, there are no offspring. This allows it to function like a genetically-encoded birth control for pest organisms."Their approach, termed Engineered Genetic Incompatibility (EGI), begins by using CRISPR/Cas9 to introduce harmless mutations into regulatory regions of DNA next to those that encode proteins. Scientists then introduce a gene-activator that looks for the original DNA sequence. When the engineered strain reproduces with a wild strain, the offspring will inherit a copy of the original sequence from their wild parent and a copy of the gene-activator from their engineered parent which causes over-activation of the wild gene copy, resulting in non-viable offspring. This method can also be used for transgene biocontainment."EGI will prove to be an invaluable tool for the safe use of GMOs. One of the risks of GMOs is the spread of transgenic material into wild populations. However, any genetic components contained within an engineered species are trapped within that species," said study co-author Nathan Feltman, a CBS graduate student in the Smanski Lab.This research builds on the team's prior work in yeast, which study co-author Siba Das -- a postdoctoral scholar in the Smanski Lab -- states marks a paradigm shift in how scientists look at engineering speciation events and how it is possible that it can be fine-tuned for desired applications."Engineering speciation events has been a long standing biotech goal and we are very excited to begin applying this method to major challenges in human and environmental health," said study co-author Maciej Maselko, Ph.D., a Research Group Leader at Macquarie University in Australia.The scientists are now working on using this technology to reduce disease-carrying and invasive mosquitoes or replace them with mosquitoes with those that cannot transmit disease. This work is specifically focused on Aedes aegypti, a mosquito that can spread Zika, dengue, chikungunya, and other viruses.This research was funded by the Defense Advanced Research Projects Agency SafeGenes Program (grant number D17AP00028).
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Animals
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September 8, 2020
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https://www.sciencedaily.com/releases/2020/09/200908113312.htm
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New insight into mammalian stem cell evolution
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The genes regulating pluripotent stem cells in mammals are surprisingly similar across 48 species, Kyoto University researchers report in the journal
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Pluripotent stem cells can self-renew and give rise to all other types of cells in the body. Their characteristics are controlled by a network of regulatory genes and molecules, but little is known about how this network has evolved across mammals.To this end, Ken-ichiro Kamei of Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS), with Miho Murayama and Yoshinori Endo of the Wildlife Research Center, compared 134 gene sets belonging to the pluripotency gene regulatory networks of 48 mammalian species.They found that this network has been highly conserved across species, meaning genetic sequences have remained relatively unchanged over the course of evolution. This high degree of conservation explains why human genetic sequences can reprogram other mammalian tissue cells to turn into pluripotent stem cells. However, since it is also evident that the regulating networks differ across mammals, there might be more efficient combinations of reprogramming factors for each species. Improving techniques for deriving induced pluripotent stem (iPS) cells from mammalian cells, including those from endangered species, could provide a big boost to research and conservation."We have been trying to generate induced pluripotent stem cells from various mammalian species, such as the endangered Grévy's zebra and the bottlenose dolphin," says Kamei.Interestingly, the team found relatively high evolutionary changes in genes just downstream of one of the core gene regulatory networks. "This could indicate that mammalian pluripotent stem cells have diversified more than we thought," says Inoue-Murayama.The differences between gene regulatory networks in mammalian pluripotent stem cells might also be associated with unique adaptions.For example, the naked mole rat has been positively selected for a pluripotency regulatory gene that could be involved in giving it its extraordinary longevity and cancer resistance. The gene might also be involved in the development of the extremely sensitive hairs that help them navigate underground.The researchers also found evidence of positive selection for certain pluripotency gene regulatory network genes involved in the adaptation of large animals, such as the minke whale, the African elephant and the flying fox, to their environments. Surprisingly, these same genes are associated with cancer in other mammals. Since these large animals are known for being relatively resistant to cancer, the researchers suggest that the adaptive alterations these genes underwent in these animals somehow also changed some of their functions, thus giving this group a degree of cancer resistance.The researchers say the study is among the first to compare the pluripotency gene regulatory networks across major taxa, and could be applicable to evolutional biology studies and for facilitating and improving the generation of induced pluripotent stem cells from new species.
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Animals
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September 8, 2020
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https://www.sciencedaily.com/releases/2020/09/200908113308.htm
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Distribution range of Ebola virus carriers in Africa may be larger than previously assumed
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The Ebola virus is considered one of the world's most dangerous pathogens. During the most severe outbreak to date in West Africa, over 11,000 deaths were documented between 2014 and 2016. Single cases are repeatedly reported from Europe as well, which are connected to previous travels to affected regions. An important source of infection are so-called reservoir hosts that carry the virus without being affected by it. For the various types of the Ebola virus, the most likely involve reservoir hosts are various species of bats and fruit bats.
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For the first time, scientists investigated where nine of such bat and fruit bat species may encounter suitable habitats and climatic conditions in Africa. "Zaire ebolavirus is one of the most dangerous Ebola viruses. It kills up to 88 percent of those infected with it. To prevent or curb outbreaks of this virus, it is essential to know exactly where potential hotspots of infection may lurk," explains parasitologist Prof. Dr. Sven Klimpel of the Goethe University in Frankfurt and the Senckenberg Biodiversity and Climate Research Centre.Based on ecological niche modeling, his team was able to show that the respective bat and fruit bat species are able to thrive in West and East Africa, including large parts of Central Africa. A wide belt of potential habitats extends from Guinea, Sierra Leone, and Liberia in the west across the Central African Republic, the Republic of the Congo and the Democratic Republic of the Congo to Sudan and Uganda in the East. A few of the studied bats and fruit bats may even occur in the eastern part of South Africa.In a second step, the researchers compared the potential habitats with range maps of the bat and fruit bat species that were generated by the International Union for the Conservation of Nature (IUCN) on the basis of observations of these animals. In addition, the team considered where a Zaire ebolavirus endemic has broken out in the past. The results were surprising: "The modeled habitats of the Zaire ebolavirus hosts are larger than their previously known ranges. It is possible that the bats and fruit bats have not yet been able to reach habitats beyond these ranges due to the presence of certain barriers," says Klimpel."Another, more worrying explanation could be that science has hitherto underestimated the range of Ebola-transmitting bat and fruit bat species. In this case, the models would provide a more realistic picture," explains Dr. Lisa Koch, the study's lead author from Goethe University. Regions affected by Ebola outbreaks often suffer not only from health effects, but also from economic and social effects of the epidemic. The study's findings suggest to keep a closer eye on diseases that occur in the modeled ranges of the reservoir hosts and to inform the public about potential Ebola infections, ultimately alleviating the consequences of an epidemic.With regard to Europe, Klimpel states: "Ebola viruses, just like the SARS-CoV-2 (Coronavirus), are viruses from the animal kingdom that can be transmitted to humans. It can be expected that diseases of this type will occur more frequently in the future, since humans have increasing contact with wild animals, and globalization facilitates the spread of viruses around the world. In Europe, with its overall efficient health system, Ebola infections are certainly going to remain isolated incidents in the future. Nonetheless, in view of these trends it would be beneficial to intensively train and further educate physicians and nursing personnel in the treatment of tropical infectious diseases in our latitudes as well."To study and understand nature with its limitless diversity of living creatures and to preserve and manage it in a sustainable fashion as the basis of life for future generations -- this has been the goal of the Senckenberg Gesellschaft für Naturforschung (Senckenberg Nature Research Society) for 200 years. This integrative "geobiodiversity research" and the dissemination of research and science are among Senckenberg's main tasks. Three nature museums in Frankfurt, Görlitz and Dresden display the diversity of life and the earth's development over millions of years. The Senckenberg Nature Research Society is a member of the Leibniz Association. The Senckenberg Nature Museum in Frankfurt am Main is supported by the City of Frankfurt am Main as well as numerous other partners.
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Animals
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September 8, 2020
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https://www.sciencedaily.com/releases/2020/09/200908113251.htm
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Why rats would win Australian survivor
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Australian rodents skulls all correspond to one simple, size-dependent shape that is more than ten million years old but it turns out this lack of change is the secret behind their survivor reputation.
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A new study, co-led by scientists from Flinders University and The University of Queensland, has revealed that the skulls of rodents resemble each other in any given size, meaning little adaptation seems to be necessary for a rodent to survive in a variety of habitats.Flinders University Associate Professor Vera Weisbecker, who supervised the study says everyone knows rodents all look similar, but researchers expected far more variety in the details of their skull shape when compared to what was found."It seems intuitive that a group of animals that displays a wide variety of shapes should be more successful in evolution. However, Australian rodents demonstrate that shape diversity doesn't always mean evolutionary success. So it really does show if the skull ain't broke, don't fix it."Dr Ariel Marcy, from The University of Queensland, says rodents first entered Australia around four million years ago, and quickly adapted to the diversity of habitats available on our continent."Because well-adapted skulls are key to the survival of mammals, we expected to find a lot of locally adapted skull shapes.""What we found was the opposite of what we expected: there was low variation in the skull shape of rodents, and body size explained most of it.""Native rodents just scale from being a small 'mouse' shape to being a bigger 'rat' shape!" Dr Marcy said."And this relationship between skull shape and size is at least ten million years old, because invasive rodents -- like the house mouse and Norway rat -- share this pattern, too."To understand the patterns of adaptation they expected to see, the team scanned hundreds of rodent skulls of 38 species from museums using 3D surface scanners, and analysed their shape using a statistical procedure called geometric morphometrics.The researchers think this astonishing conservatism of shape may have to do with the very successful specialization of rodent jaws, allowing their skulls to be a true multi-purpose tool."Rodent skulls and jaws have a complicated yet highly versatile arrangement that seems to work well in a multitude of conditions. We think that this discourages evolutionary change. We saw unusual skull shapes only in extreme cases of ecological adaptation, for example in the water mouse or rakali which is a very unusual meat-eating predatory rodent."Dr Weisbecker notes that the results make an important point in one of the biggest questions in evolutionary biology -- why some groups of animals are more diverse than others.
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Animals
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September 7, 2020
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https://www.sciencedaily.com/releases/2020/09/200907080346.htm
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African wild dogs have vestigial first digit and muscular adaptations for life on the run
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African wild dogs have a vestigial first digit and muscular adaptations for life on the run
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Anatomists identify a vestigial first digit in the forelimb of the African wild dog and document anatomical adaptations to its unique lifestyle of long-distance running and exhaustive predationAfrican wild dogs (Lycaon pictus) are known for their unique hunting style, often referred to as "exhaustive predation," in which they chase their prey to exhaustion, rather than hunting using speed, strength, or stealth. They are also unique among the dog clade in having only four full digits on their front paws. Until recently, it was unclear how these unique behavioral and anatomical features would affect their forelimb morphology.The African wild dog, also known as the African painted dog or Cape hunting dog, is native to southern and eastern Africa, and classified as Endangered by the International Union for the Conservation of Nature (IUCN). They use sophisticated, coordinated hunting behaviors in which some packs decide as a group to hunt and communicate their vote via "sneezing." They also have a nomadic lifestyle with packs traveling up to 50 km per day and geographically extensive home ranges of 560 to 3000 km2. African wild dogs also differ from other canid (dog) species in the absence of a fully formed first digit (tetradactyly), which may allow for increased speed and stride length, facilitating long-distance pursuit of prey.In a recent study published in The authors have also discovered a stout ligament in the wrist which may act as a strut, assisting with passive flexion and rebound of the forefoot. This taut ligament provides non-muscular propulsion during push-off of the forepaw, which may help sustain endurance running and prevent the wrist muscles from tiring. This morphology is similar in function to the suspensory ligaments of the horse "spring foot," which provides passive "spring" action by absorbing and transferring forces experienced during locomotion.Several other muscular adaptations to long-distance endurance running in the forelimb muscles have also been identified, including relatively reduced wrist rotator muscles and thick ligaments binding the radius and ulna (the two forearm bones), resulting in greater wrist and forearm stability. Several muscles associated with joint stability elastic energy storage during locomotion are also expanded compared to other species.According to Smith, "This is the first in-depth study of African wild dog forelimb anatomy, and it demonstrates multiple adaptive mechanisms of endurance running, including reconfiguration of forelimb muscles, ligaments, and even bones, which function synchronously to facilitate the highly cursorial lifestyle of this fascinating species."
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Animals
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September 8, 2020
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https://www.sciencedaily.com/releases/2020/09/200908093742.htm
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Protected areas can 'double' imperilled species populations
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A University of Queensland-led research team has revealed that many endangered mammal species are dependent on protected areas, and would likely vanish without them.
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Professor James Watson, of UQ and the Wildlife Conservation Society, said despite the success of protected areas, their popularity as a go-to conservation tool has started to wane."Since the 1970s, the global network of protected areas has experienced a fourfold expansion, and some of these protected sites have been crucial to protect and even enhance wildlife populations," he said."However, there's increasing debate around the role of the global protected area estate in sustaining and recovering threatened species."What our research has clearly shown is that protected areas, when well-funded and well-placed, are incredibly effective."In fact, 80 per cent of mammal species we monitored in these protected areas have at least doubled their coverage in protected areas over the last 50 years."And 10 per cent of the species analysed live predominantly on protected land."The scientists compared current distributions of 237 threatened terrestrial mammal species from the 1970s to today, measuring changes in species' ranges, then overlaid them with the protected area network."A great example is the greater one-horned rhinoceros (Rhinoceros unicornis), which now has 80 per cent of its range in a protected area," Professor Watson said."Their numbers have been decimated elsewhere -- the species has lost more than 99 per cent of its distribution in the last 50 years."Now about 87 per cent of the remaining animals live in just two protected areas -- Kaziranga National Park in India and Chitwan National Park in Nepal."Professor Watson said mammals were retreating into protected areas and more than ever, protected areas were vital to protecting the world's biodiversity."There is little doubt that without protected areas we would have lost amazing species like tigers and mountain gorillas," he said."This science clearly shows that to abate the extinction crisis, we need better funded and more protected areas that are well-supported and well-managed by governments and other land managers."At the same time, we need to reward efforts that ensure re-expansion and restoration of wildlife populations into territories beyond protected area boundaries."We must focus on retaining Earth's remaining intact ecosystems that contain key protected areas and prioritise efforts to restore habitat corridors between isolated reserves, providing opportunities for movement and genetic exchange."
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Animals
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September 4, 2020
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https://www.sciencedaily.com/releases/2020/09/200904090306.htm
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Striving and stumbling towards sustainability amongst pandas and people
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The path to global sustainability isn't a one-way street and scientists at Michigan State University and in China use the world's adoration of pandas to show new ways to figure out how not to get lost.
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The group scrutinized the complex, vast enterprises that feed the boundless love of giant pandas that bring tourists to the Wolong Nature Reserve and other reserves in remote southwestern China, and the successful operations that loan the cuddly bears to zoos all over the world. The goal: understand how achieving one of the 17 United Nations' Sustainable Development Goals (SDGs) spins off more SDG success -- or sabotages progress on another goal across spatial and administrative boundaries, as well as unforeseen consequences.But that's only the beginning, says the group writing in "Previous research indicates that efforts towards the SDGs have an inherent tendency to achieve one at the cost or benefit of others in a specific place," said senior author Jianguo "Jack" Liu, Rachel Carson Chair in Sustainability and director of the Center for Systems Integration and Sustainability. "but it is not clear how SDGs interact across boundaries although the world is increasingly interconnected among different places and the SDGs need to be achieved everywhere. To fill such an important knowledge gap, we have developed new ways to understand SDG tradeoffs and synergies within and across boundaries. Interactions between pandas and people are very useful for exploring this new interdisciplinary frontier."To find the synergies and tradeoffs that swell around panda endeavors, the group examined a wide range of information surrounding tourism in and around Wolong, as well as 19 other panda reserves in Sichuan Province who were visited by more than 8.2 million tourists annually. They discovered that tourism brought nine synergies amongst the SDGs, with various aspects of economic growth being promoted, which in turn alleviated poverty, raised incomes, improved infrastructures. One SDG took a hit, as hiking trails for tourists disturbed crucial panda habitat.From 1996 to 2017, Wolong implemented international collaboration agreements with 14 zoos in 12 countries andSDGs_Panda_tourism_2020 sent 28 pandas to those zoos, and that effort created win-win situations for SDGs, both providing economic boosts as well as funding scientific research and supporting training bases for panda reintroduction.The authors further revealed that the benefits spilled over beyond the reserves' borders, as people who live outside created businesses and made money supporting the tourism effort. Hitting one SDG had the domino effect of providing progress for other goals as people found jobs and improved their lives. The industry that took a chunk out of another goal was the collection of medicinal herbs. While that provided economic benefits to people, that activity damaged natural habitat.The panda loans, they found, have generated income that has enhanced scientific research -- and then generated positive results that have spilled over into benefits for other reserves to have more resources for conservation, which in turn allowed more pandas to be reintroduced in the wild and boost genetic diversity."We have found many more synergies than trade-offs when it comes to striving for Sustainable Development Goals," said Zhiqiang Zhao, lead author of the paper. "It is important to cast a wide net when understanding what battles we are winning in sustainability, and what wins may be at a cost of another important goal. Only then can we make necessary adjustments."Besides Liu and Zhao, the paper "Synergies and trade-offs among Sustainable Development Goals across boundaries in a metacoupled world" was written by Meng Cai, Fang Wang, Julie Winkler, Thomas Connor, Min Gon Chung, Jindong Zhang, Hongbo Yang, Zhenci Xu and Ying Tang, who all are, or recently have been, affiliated with MSU, and Zhiyun Ouyang, and Hemin Zhang in China.The work is funded by the National Science Foundation; MSU AgBioResearch; and the State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences.
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Animals
| 2,020 |
September 4, 2020
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https://www.sciencedaily.com/releases/2020/09/200904092930.htm
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Do big tadpoles turn into big frogs? It's complicated
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If you have any children in your life, imagine for a moment that they don't look anything like their parents, they don't eat anything humans normally eat, and they're active only while adults sleep.
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While that might sound like an idea from a work of surreal fiction, it's actually the norm rather than the exception in the animal kingdom. Most animals go through what biologists call a complex life cycle, starting as larvae that often have little, if anything, in common with their parents.To become adults, they have to go through a process known as metamorphosis, which is one of nature's most remarkable feats. During this process, the larval bodies of many animal species undergo dramatic changes that turn them into adults that have little, if any resemblance with their juvenile stage. Butterflies may be the most familiar example of this. Yet, despite complex lifecycles being widespread, surprisingly little is known about how they evolve, specifically the extent to which evolution in one life stage impacts the others.To better understand the evolutionary consequences of a complex life cycle across a large group of related species, University of Arizona biologists studied another familiar example: frogs and their tadpoles.Tung Phung, Joao C. S. Nascimento and John J. Wiens of the UArizona Department of Ecology and Evolutionary Biology took a closer look at the evolution of body size across 542 frog species belonging to 42 families, most of which have a tadpole stage. The study, which was co-authored by Alexander Novarro of The Nature Conservancy, is published in the scientific journal "We wanted to know, do large frogs have large tadpoles and small frogs small tadpoles, or are the sizes between the two decoupled?'" Wiens said, alluding to a prevailing hypothesis in evolutionary biology that states that larvae and adults should evolve rather independently, especially in species in which the two life stages have very different lifestyles.If larval and adult stages evolve completely independently of each other, there should be little correlation between larval size and adult size among species. In other words, big frogs could have little tadpoles, and big tadpoles could become small frogs, with no relationship between the size of frogs and tadpoles.The team scoured the scientific literature for data on the sizes of tadpoles and adult frogs for each species, assembled an evolutionary tree among the species, and applied statistical analytical tools.The team discovered that while there is a striking amount of variability among frog families, the association is not completely random. Across frogs as a group, larval and adult body sizes are significantly and positively related."It's not just 'anything goes,'" Wiens said. "We included almost every family of frogs that has a tadpole stage, and we did find there is constraint. In some cases, it's really strong; adult size strongly predicts larval size in many of the families we looked at."In other families included in the study, the researchers found the relationship to be much more variable. For example, in the spadefoot toad (Scaphiopodidae) family, species with large adults have small tadpoles and species with small adults have large tadpoles.There was also variation in the relative size of adults and tadpoles among families. For example, the paradox frog, Pseudis paradoxa, is a species with normal-sized adults that develop from giant tadpoles that are three to four times bigger than the adult. On the other end of the spectrum are some giant South American toads, whose tadpoles are about a tenth the size of the adult."Overall, the size of tadpoles relative to adults changes widely across frogs, but why, we don't know," Wiens said.The authors also compared the rates of evolution in body sizes between tadpoles and adults. These were found to be clearly decoupled. For example, in glass frogs, the tadpole stage runs a broad gamut of sizes, indicating it has been evolving very quickly, while the adults vary much less in size. Other groups, such as the true toads, have fast evolutionary rates in both stages, while yet others, such as the African bullfrogs, show the opposite pattern, with adults evolving fast and tadpoles changing slowly.Once tadpoles, which are confined to water, morph into frogs that spend most of their time hopping around on land, their bodies undergo an extreme makeover: The tissues that make up their powerful tail, used to propel them underwater, are recycled into other tissues; appendages begin sprouting beginning with the legs, then the arms, and they lose their feeding apparatus. This feeding system usually consists of a big beak, bordered by five or more rows of tiny teeth, which themselves are surrounded by a ring of short, fleshy tentacles. Inside, a filter system uses streams of slime to extract food from the water. Some tadpoles seem to use the teeth and beak to scrape algae off of rocks. Others suck up decaying organic matter from the bottoms of their freshwater habitats. But some tadpoles are carnivorous and may even be cannibalistic."Their feeding mechanism is so weird that people still don't know exactly how it works or even what most tadpoles eat," Wiens said. "In adult frogs, the mouthparts are completely different, so they have to take this whole system down and rebuild during metamorphosis."While the huge variability in tadpole size relative to adults makes frogs especially interesting to Wiens and his research team, he said another reason for choosing frogs for this study was their status as endangered animals that are highly beneficial to the natural environment.Of the more than 7,200 frog species that have been described, most live in the tropics, and many have been disappearing at an alarming rate, Wiens said. This is worrisome as they play critical roles in ecosystems across the globe -- for example, acting as a natural pest control."Many of them eat insects that destroy crops, so they are really useful that way," he said.While the current study is limited to amphibians, it does open up questions for other groups of animals, said the paper's first author, Tung Phung, a first-year doctoral student in Wiens' lab who did most of the work while still an undergraduate."Our study is the first to address evolutionary rates of larval and adult life stages at a large scale," he said.
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Animals
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September 3, 2020
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https://www.sciencedaily.com/releases/2020/09/200903145006.htm
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Hearing loss in naked mole-rats is an advantage, not a hardship
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If naked mole-rats were human, they would be prescribed hearing aids. With six mutations in genes associated with hearing, naked mole-rats can barely hear the constant squeaking they use to communicate with one another. This hearing loss, which is strange for such social, vocal animals, is an adaptive, beneficial trait, according to new findings published in the journal
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Naked mole-rats are East African hairless mammals that are bald and wrinkly with buck teeth. They live in underground colonies and their social structure resembles that of bees -- there are soldiers, workers and a queen. A lot of cooperation is required for a mole-rat colony to function. Naked mole-rats need to decide where to dig, how to defend the colony, and how to convey the location of food sources, and much of this is accomplished by vocal communication."Naked mole-rats are constantly chirping and squeaking," said Thomas Park, professor of biological sciences and neuroscience at the University of Illinois Chicago and one of the lead authors on the paper.Park has been studying naked mole-rats for decades and has described some of their odd traits, such as their ability to thrive under conditions of low oxygen underground and their high tolerance for pain."We were curious about their hearing since they are so vocal, but research had suggested that their hearing is actually quite bad," Park said.Park and colleagues tested the hearing of mole-rats using technology similar to that used for testing human hearing. They performed an auditory brain stem response test, during which electrodes placed on the scalp pick up signals indicative of sound being processed in the brain. The researchers found the signals were weak, confirming naked mole-rats have poor hearing. In fact, "their hearing is so bad that they would be candidates for hearing aids if they were people," Park said.Once the hearing loss was confirmed, Park and colleagues turned to the mole-rats' genetics and found six mutations in genes associated with hearing loss in humans."The fact that there were so many of these mutations strongly suggests that these mutations were selected for because they are adaptive in some way," Park explained.The researchers also found the naked mole-rats lacked cochlear amplification, a process by which specialized cells in the inner ear help amplify sound signals before those signals are sent to the brain. Cochlear amplification is aided by cells called outer hair cells, which are located in the inner ear. Without proper functioning of these cells, sounds are severely dampened."If the naked mole-rats didn't have these mutations, the constant noise they produce could actually kill the hair cells responsible for hearing," Park said.Hair cells receive auditory vibrations and send signals to the brain where they are interpreted as sound. Really loud sounds actually kill hair cells, which, unlike other types of cells, can't regenerate. Park said this is why hearing loss in most mammals is progressive."Because the naked mole-rats lack functional cochlear amplification, the sounds they hear don't ever get up to a level where they are lethal to hair cells, and so the naked mole-rats can withstand this constant cacophony without going totally deaf," Park said. "They are the only mammals we know of that lack cochlear amplification."The new findings suggest that mole rats may be a good animal model to investigate hearing loss in humans.
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Animals
| 2,020 |
September 3, 2020
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https://www.sciencedaily.com/releases/2020/09/200903114210.htm
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Old males vital to elephant societies
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Old male elephants play a key role in leading all-male groups, new research suggests.
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Trophy hunters justify targeting older bull elephants on the grounds they are "redundant" in terms of breeding and hence species survival.But the new study, by the University of Exeter, shows the oldest bulls in all-male groups are the most likely to hold leading positions when the elephants travel, potentially helping younger, less experienced followers find food and water.The study, in collaboration with Elephants for Africa, examined the movements of male African savannah elephants (also known as bush elephants) in Makgadikgadi Pans National Park, Botswana."Our results challenge the assumption that older male elephants are redundant in the population and raise concerns over the removal of old bulls that currently occurs in both legal trophy hunting and illegal poaching," said lead author Connie Allen, of Exeter's Centre for Research in Animal Behaviour."We argue that selective hunting of old bulls is not sustainable."Past research has shown in fact that old bulls are the prime breeders (they sire the most offspring) in African elephants."Our findings suggest that killing them could also have detrimental effects on wider elephant society through loss of leaders who help young, newly independent males navigate in unfamiliar, risky environments."Pre-adolescent male African savannah elephants live in herds led by females, but between age 10-20 they leave their natal family, spending most of their time in all-male groups.The study divided male elephants into age groups (10-15, 16-20, 21-25 and 26+) and found probability of leadership -- measured by which elephant walked at the front of travelling groups -- increased along with age."Research on benefits of older individuals in long-lived social mammals has largely focused on females in matrilineal societies where, for example, older female elephants are most effective at making decisions crucial to herd survival, and old post-reproductive female killer whales lead collective movements in hunting grounds," said Professor Darren Croft, of the University of Exeter."In contrast, less is known about the role of older males as leaders in long-lived social species."Our study suggests that bull elephants occupy a similar leadership role in male elephant society as old female matriarchs in breeding herds -- and so they may require equal protection."Associate Professor Lauren Brent, of the University of Exeter, said: "This work highlights the need to examine other ways that younger males learn from experienced older males in long-lived mammals."Poaching, hunting and conflict with humans (such as killing by farmers) are the main causes of death among mature bull elephants, and their numbers are declining rapidly.Older male elephants are usually targeted by trophy hunters as they have larger tusks, and often minimum ages are implemented by hunting operators.Botswana has recently announced a decision to recommence elephant trophy hunting, and export quotas for the tusks of 400 elephants have been issued for this year."The intricacies of male elephant societies have often been ignored in management and conservation decisions with the underlying assumption that once they leave their herd they are solitary and independent," said Dr Kate Evans, director of Elephants for Africa and a member of the Gothenburg Global Biodiversity Centre. "This study furthers our understanding of male elephants and the importance of older bulls, enabling more sustainable management decisions for both male and female elephants to be made."The study was supported by the Leverhulme Trust, The Explorers Club, Wilderness Wildlife Trust, IDEAWILD and Elephants for Africa.
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Animals
| 2,020 |
September 3, 2020
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https://www.sciencedaily.com/releases/2020/09/200903075924.htm
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New test can detect crown-of-thorns starfish as quickly as a home pregnancy kit
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Researchers at the Australian Institute of Marine Science have developed a dipstick test that can detect crown-of-thorns starfish (CoTS) on coral reefs by using the same technology as home pregnancy tests.
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The dipstick, which is designed to be used in the field, measures specific DNA that CoTS release into the seawater. The rapid test can detect very low numbers of the coral-eating pest, which can be difficult to spot with current survey methods.AIMS biochemist and the study's lead author Jason Doyle said the sensitive test could support an early warning and intervention system for future CoTS outbreaks. It could also enable citizen scientists, tourism operators and Great Barrier Reef managers to help with early warnings."It's the sort of technology we would love to get out to as many people as possible, because the more people that are doing this kind of test, the more information we have about the location of CoTS and the better management outcomes we can achieve," Mr Doyle said.An average adult CoTS (Acanthaster cf. solaris) can eat up to a dinner-plate amount of coral every day, and outbreaks contribute considerably to the loss of corals on the Great Barrier Reef. There have been three outbreaks since 1962, with a fourth outbreak currently underway.The native starfish often hide under or on coral plates, while younger CoTS can be as small as a couple of millimeters. This makes it harder for traditional diver surveys to spot the creatures and identify emerging outbreaks.The dipstick test research, published in the journal "Organisms leave a genetic shadow wherever they go, so we use the genetic shadow of CoTS in seawater to flag the presence of both adults and babies," Mr Doyle said. "But if this technique was really going to be an early warning system, we needed to bring our validated tools for environmental DNA (eDNA) detection out of the lab and into the hands of non-lab people in the field."For their recent study, Mr Doyle and his AIMS colleague Dr Sven Uthicke turned to the world of human diagnostics for the answer. They adapted an off-the-shelf dipstick and a technology called Lateral Flow Assay (LFA) to detect DNA in marine environments. LFA has been used for many years in home blood sugar and pregnancy tests, and more recently for Coronavirus tests.The new test can measure very small amounts of CoTS DNA, down to 0.1 picograms, making it potentially sensitive to very low densities of the animal. Like its human-diagnostic counterparts, the CoTS dipstick tests reveal a positive response via the appearance of a stripe.Researchers collected seawater samples from Lizard Island, north of Cairns, and Elizabeth Reef, north of Mackay, and found CoTS DNA where traditional survey methods did not find any of the animals.Mr Doyle said the study was the first step in developing a tool that could eventually require just a few drops of seawater to detect CoTS. He also stressed that the new method is not an alternative to survey methods but would enhance their cost effectiveness."We see it as a way to raise the red flag so we know there's probably a good reason to get people in the water in this spot, but not that spot over there, maximising the use of resources such as divers, boats and other infrastructure," he said.This research was supported by a National Geographic Society grant and the Ian Potter Foundation.
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Animals
| 2,020 |
September 2, 2020
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https://www.sciencedaily.com/releases/2020/09/200902230732.htm
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Researchers identify five types of cat owner
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Cat owners fall into five categories in terms of their attitudes to their pets' roaming and hunting, according to a new study.
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University of Exeter researchers surveyed UK cat owners and found they ranged from "conscientious caretakers" concerned about cats' impact on wildlife and who feel some responsibility, to "freedom defenders" who opposed restrictions on cat behaviour altogether."Concerned protectors" focussed on cat safety, "tolerant guardians" disliked their cats hunting but tended to accept it, and "laissez-faire landlords" were largely unaware of any issues around cats roaming and hunting.Conservation organisations have long been concerned about the numbers of animals caught by the UK's large population of domestic cats.Most pet cats kill very few wild animals, if any, but with a population of around 10 million cats, the numbers of birds, small mammals and reptiles taken can accumulate.Apart from their role as "mousers," most owners find the dead animals brought home an unpleasant reminder of their pet's wilder side.Addressing this problem has been difficult because of disagreements between people prioritising cat welfare and those focusing on wildlife conservation.The Exeter team's ongoing research project "Cats, Cat Owners and Wildlife" aims to find a conservation win-win, by identifying ways of owners managing their cats that benefit the cats as well as reducing wildlife killing.This research is a step towards understanding how cat owners view their cats and how best to manage them.The researchers say their findings demonstrate the need for diverse management strategies that reflect the differing perspectives of cat owners."Although we found a range of views, most UK cat owners valued outdoor access for their cats and opposed the idea of keeping them inside to prevent hunting," said lead author Dr Sarah Crowley, of the University of Exeter's Environment and Sustainability Institute in Cornwall."Cat confinement policies are therefore unlikely to find support among owners in the UK."However, only one of the owner types viewed hunting as a positive, suggesting the rest might be interested in reducing it by some means."To be most effective, efforts to reduce hunting must be compatible with owners' diverse circumstances."Suggested measures to reduce hunting success include fitting cats with brightly coloured "BirdsBeSafe" collar covers. Many owners also fit their cats with bells.The research team are now examining the effectiveness of these and other new measures and how owners feel about them, with a view to offering different solutions."This latest research we have funded reveals the incredibly diverse perspectives amongst cat owners in regard to their pets' hunting behaviour," said Tom Streeter, Chairman of SongBird Survival."If nature is to 'win' and endangered species thrive, a pragmatic approach is needed whereby cat owners' views are considered as part of wider conservation strategies."The study highlights the urgent need for cat owners and conservationists to work together to find tailored solutions that are cheap, easy to implement, and have a positive effect on wildlife and bird populations across the UK."iCatCare's Head of Cat Advocacy, Dr Sarah Ellis, said: "The finding that many UK cat owners actually care a great deal about wildlife conservation and their cats' impact on it, suggests that some owners are receptive to employing cat-friendly ways of reducing hunting."The right interventions could improve wildlife conservation efforts, maintain good cat mental-wellbeing, and at the same time improve the cat-human relationship."This would be especially true for 'tolerant guardians' and 'conscientious caretakers', by reducing the internal conflict of loving an animal that often hunts other animals they also care about."The study included 56 cat owners, some from rural parts of the UK (mostly in south-west England) and some from urban areas (Bristol and Manchester).The paper, published in the journal Alongside the detailed research survey, the researchers have created a simple quiz so cat owners can find out which category bests describes them.
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September 1, 2020
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https://www.sciencedaily.com/releases/2020/09/200901164453.htm
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Eye of a fly: Researchers reveal secrets of fly vision for rapid flight control
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By examining how fruit flies use eye movements to enhance flight control with a staggeringly fast reaction speed -- about 30 times faster than the blink of an eye -- Penn State researchers have detailed a framework to mimic this ability in robotics.
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The researchers described the motions of fruit flies tethered in a virtual reality flight simulator constructed with LED lights and recorded using high speed cameras, in a paper published today (Aug. 31) in the "If you are able to study flies doing what they do best -- flying -- you can find some incredible engineering solutions that already exist in biology," said Benjamin Cellini, a doctoral student studying mechanical engineering and the first author of the paper.Cellini and his adviser, Jean-Michel Mongeau, assistant professor of mechanical engineering and the director of the Bio-Motion Systems Lab, were able to determine how fruit flies use eye movements to quickly coordinate their wings in response to what they were seeing. Since fly eyes are fixed to the head, the researchers tracked head movements to infer where the flies were looking.Stabilizing gaze is an ordinary phenomenon that most living things can do. For instance, we seamlessly move our eyes, head and/or body to scan a room."But that is a challenging, complex problem to understand, how are we and other animals able to do that so well?" Mongeau said. "My lab is interested in active sensing, which is a branch of engineering and biology that studies how sensor movement, like eyes scanning a room, can enhance sensing itself."While much of the previous research in this area has focused on wing movements, understanding how animals like flies use active eye movements to control flight could greatly enhance robotics. Currently, most robots have stationary sensors, keeping sensing and movement decoupled. However, by better emulating the eyes and brain through the coordination of visual sensors capable of moving on the body, the flight control of robots could be vastly improved.In support of this theory, the researchers determined the eyes of the fruit fly were able to react four times faster than the body or wings of the animal. These reactions were also tightly coupled, demonstrating that flies rely heavily upon eye movements to coordinate their wing movements."We've shown that their eyes can control and stabilize their vision better than we originally thought, by reducing motion blur," Cellini said. "Like in sports, they teach baseball players to follow the ball with their eyes to reduce blur and increase batting performance."In addition, they found that when the flies had glue carefully applied to their heads and then recorded in the virtual reality flight simulator, the restriction of their head movements had a dramatic impact on flight performance."An important principle we discovered here was that fly eyes slow down visual motion that go into the brain and this process enhances their flying behavior," Mongeau said.Demonstrated in this work, the researchers believe unlocking the secrets of the biological world could have broad implications for technology."In engineering, you are taught to apply principles from mathematics and physics to solve problems," Cellini said. "If you want to build a robot to fly on Mars, you can use engineering concepts to provide potential solutions. But we don't always have to develop ideas from scratch; we can also seek inspiration from nature."A grant from the Air Force Office of Scientific Research supported this research.
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September 1, 2020
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https://www.sciencedaily.com/releases/2020/09/200901142727.htm
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Differing diets of bonobo groups may offer insights into how culture is created
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Human societies developed food preferences based on a blend of what was available and what the group decided it liked most. Those predilections were then passed along as part of the set of socially learned behaviors, values, knowledge, and customs that make up culture. Besides humans, many other social animals are believed to exhibit forms of culture in various ways, too.
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In fact, according to a new study led by Harvard primatologists Liran Samuni and Martin Surbeck, bonobos, one of our closest living relatives, could be the latest addition to the list.The research, published today in Analyzing the data, the scientists saw many similarities in the lives of the two bonobo groups, given the names the Ekalakala and the Kokoalongo. Both roam the same territory, roughly 22 square miles of forest. Both wake up and fall asleep in the bird-like nests they build after traveling all day. And, most importantly, both have the access and opportunity to hunt the same kind of prey. This, however, is precisely where researchers noticed a striking difference.The groups consistently preferred to hunt and feast on two different types of prey. The Ekalakala group almost always went after a type of squirrel-like rodent called an anomalure that is capable of gliding through the air from tree to tree. The Kokoalongo group, on the other hand, favored a small to medium-sized antelope called a duiker that lives on the forest floor."The idea is that if our closest living relatives, chimpanzees and bonobos, both have some cultural traits, then [it's likely] our ancestors already had some capacity for culture." -- Liran SamuniOut of 59 hunts between August 2016 and January 2020, the Ekalakala captured and ate 31 anomalure, going after duikers only once. Kokoalongo ate 11 duikers in that time and only three gliding rodents."It's basically like two cultures exploiting a common resource in different ways," said Samuni, a postdoctoral fellow in Harvard's Pan Lab and the paper's lead author. "Think about two human cultures living very close to each other but having different preferences: one preferring chicken more while the other culture is more of a beef-eating culture. ... That's kind of what we see."Using statistical modeling, the scientists found this behavior happens independent of factors like the location of the hunts, their timing, or the season. They also found the preference wasn't influenced by hunting party size or group cohesion. In fact, the researchers' model found that the only variable that could reliably predict prey preference was whether the hunters were team Ekalakala or team Kokoalongo.The researchers make clear in the paper that they didn't investigate how the bonobo groups learned this hunting preference, but through their analysis they were able to rule out ecological factors or genetic differences between the two groups. Basically, it means all evidence points toward this being a learned social behavior."It's the same population, and it's neighboring communities," said Surbeck, an assistant professor in the Department of Human Evolutionary Biology and the paper's senior author. He founded and directs the Kokolopori Bonobo Research Project. "These two communities basically live in the same exact forest. They use the exact same places, but, nevertheless, they show these differences."The paper amounts to what's believed to be the strongest evidence of cultural behavior in this primate species.The researchers believe this paper is only the tip of the iceberg and are already planning the next part of the work: looking at how the bonobo groups learned these behaviors.One of the main goals driving this work is helping characterize the cultural capabilities of the last common ancestor between humans and our two closely related great ape cousins."The idea is that if our closest living relatives, chimpanzees and bonobos, both have some cultural traits, then [it's likely] our ancestors already had some capacity for culture," Samuni said.Bonobos can play a special role in this mystery. Like chimpanzees, which they are often mistaken for, bonobos share 99 percent of their DNA with humans. Bonobos are often seen as less aggressive and territorial, however, favoring sex in various partner combinations over fighting. Chimp groups, on the other hand, sometimes battle when they meet in the wild, occasionally to the death.Different Bonobo population groups are known to interact and even share meals, which along with their socio-sexual behavior has earn them the moniker "hippie apes." It's those free love and peace traits that make them prime for this type of study since scientists can observe two neighboring bonobo groups to distinguish whether a behavior that differs between two groups that interact regularly comes about because of some sort of a learning mechanism (or social preference) or because the environment dictates it, the researchers said.The authors of the paper were not much surprised by their findings.They had noticed this hunting preference anecdotally, and it's already believed that bonobos have subtle cultural traits. After all, a number of social animals display cultural behavior, especially when it comes to feeding habits. Chimps teach their young to use sticks to fish for termites. Dolphin mothers teach offspring to fit marine sponges to their noses to protect them as they forage on the seafloor.What excites the researchers about this discovery, however, is that it shows the value of studying this often-overlooked endangered species and diving into its culture."They're like the missing puzzle piece," Surbeck said.
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Animals
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September 1, 2020
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https://www.sciencedaily.com/releases/2020/09/200901130719.htm
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Earliest fossil evidence of an insect lichen mimic
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Scientists have uncovered the earliest known evidence of an insect mimicking a lichen as a survival strategy, according to new findings published today in
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The study suggests that the Jurassic moth lacewing Lichenipolystoechotes mimicked the fossil lichen Daohugouthallus to help conceal itself from predators. This interaction predates modern lichen-insect associations by 165 million years, indicating that the lichen-insect mimicry (or 'mimesis') system was well established during the mid-Mesozoic period and provided lacewings with highly-honed survival strategies.Animals sometimes mimic other organisms or use camouflage to deceive predators. Lichens, which consist of a fungus and alga living in close proximity, sometimes have a plant-like appearance and are occasionally mimicked by modern animals and insects. One of the most well-known cases of a lichen-insect association is when the peppered moth acquired a mutation that turned it black during the Industrial Revolution in Britain, allowing the moth to blend in with tree trunks and lichen darkened by soot."As lichen models are almost absent in the fossil record of mimesis, it is still unclear as to when and how the mimicry association between lichen and insect first arose," explains lead author Hui Fang, a PhD student at the College of Life Sciences and Academy for Multidisciplinary Studies, Capital Normal University, Beijing, China. "The key to answer this question is to find early examples of a lichen-like insect and a co-occuring lichen fossil."Fang and her team discovered deposits at the Daohugou 1 locality of Inner Mongolia in northeastern China that showed the 165-million-year-old lichen mimesis. The samples involved two lacewing species resembling a co-existing lichen from the latest Middle Jurassic.After confirming the occurrence of the Jurassic lichen, the team then documented this mimetic relationship by describing structural similarities and detailed measurements of the lacewing and lichen. Their results suggest that when the lacewings rested in a lichen-rich habitat, a near-perfect match of their appearances would assist the insects' concealment from predators."Our findings indicate that a micro-ecosystem consisting of lichens and insects existed 165 million years ago in Northeastern China," concludes senior author Yongjie Wang, Associated Professor at the College of Life Sciences and Academy for Multidisciplinary Studies, Capital Normal University, Beijing. "This adds to our current understanding of the interactions between insects and their surroundings in the Mesozoic Era, and implies that there are many more interesting insect relationships awaiting discovery."
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September 1, 2020
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https://www.sciencedaily.com/releases/2020/09/200901120731.htm
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Neglected for over a century, Black sea spider crab re-described
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Even though recognised in the Mediterranean Sea, the
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Now, scientists re-describe this, most likely, only species of the genus occurring in the Black Sea in the open-access journal The spider crab genus After the revision of available type specimens from all available collections in the Russian museums and the Senckenberg Museum in Frankfurt-on-Main, as well as newly collected material in the Black Sea and the North-East Atlantic, a research team of scientists, led by Dr Vassily Spiridonov from Shirshov Institute of Oceanology of Russian Academy of Sciences, re-described "The analysis of the molecular genetic barcode (COI) of the available material of All "It improves our understanding of its invasion history. Museum and monitoring collections of species with abundant epibiosis (in particular inachid crabs) can be used as an additional tool to record and monitor introduction and establishments of sessile non-indigenous species," suggests Dr Spiridonov.
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Animals
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September 1, 2020
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https://www.sciencedaily.com/releases/2020/09/200901112207.htm
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How to weigh a dinosaur
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How do you weigh a long-extinct dinosaur? A couple of ways, as it turns out, neither of which involve actual weighing -- but according to a new study, different approaches still yield strikingly similar results.
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New research published September 1 in the journal The findings should give us some confidence that we are building an accurate picture of these prehistoric animals, says study leader Dr. Nicolás Campione -- particularly our knowledge of the more massive dinosaurs that have no correlates in the modern world."Body size, in particular body mass, determines almost at all aspects of an animal's life, including their diet, reproduction, and locomotion," said Dr. Campione, a member of the University of New England's Palaeoscience Research Centre."If we know that we have a good estimate of a dinosaur's body mass, then we have a firm foundation from which to study and understand their life retrospectively."Estimating the mass of a dinosaur like the emblematic The research team led by Dr. Campione compiled and reviewed an extensive database of dinosaur body mass estimates reaching back to 1905, to assess whether different approaches for calculating dinosaur mass were clarifying or complicating the science.Although a range of different methods to estimating body mass have been tried over the years, they all come down to two fundamental approaches. Scientists have either measured and scaled bones in living animals, such as the circumference of the arm (humerus) and leg (femur) bones, and compared them to dinosaurs; or they have calculated the volume of three-dimensional reconstructions that approximate what the animal may have looked like in real life. Debate over which method is 'better' has raged in the literature.The researchers found that once scaling and reconstruction methods are compared "In fact, the two approaches are more complementary than antagonistic," Dr. Campione said.The bone scaling method, which relies on relationships obtained directly from living animals of known body mass, provides a measure of accuracy, but often of low precision; whereas reconstructions that consider the whole skeleton provide precision, but of unknown accuracy. This is because reconstructions depend on our own subjective ideas about what extinct animals looked like, which have changed appreciably over time."There will always be uncertainty around our understanding of long-extinct animals, and their weight is always going to be a source of it," said Dr. David Evans, Temerty Chair of Vertebrate Palaeontology at the Royal Ontario Museum in Toronto, senior author on the new paper. "Our new study suggests we are getting better at weighing dinosaurs, and it paves the way for more realistic dinosaur body mass estimation in the future."The researchers recommend that future work seeking to estimate the sizes of Mesozoic dinosaurs, and other extinct animals, need to better-integrate the scaling and reconstruction approaches to reap their benefits.Drs. Campione and Evans suggest that an adult "It is only through the combined use of these methods and through understanding their limits and uncertainties that we can begin to reveal the lives of these, and other, long-extinct animals," Dr Campione said.
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September 1, 2020
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https://www.sciencedaily.com/releases/2020/09/200901093404.htm
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Monitoring and reporting framework to protect World Heritage Sites from invasive species
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A team of international scientists have devised a new monitoring and reporting framework to help protect World Heritage Sites from almost 300 different invasive alien species globally including, rats (Rattus spp.), cats (Felis catus), lantana (
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Lead author Dr Ross Shackleton joined invasive species experts from around the globe -- including CABI's Dr Arne Witt -- who suggest the new 'tool' could ultimately help protect World Heritage Sites like the Galápagos, Serengeti and Aldabra Atoll from future threats.UNESCO World Heritage Sites, are areas of outstanding universal value and conservation importance. However, they are threatened by a variety of global change drivers, including biological invasions from a range of terrestrial, freshwater and marine-based invasive alien species.The team, who assessed biological invasions and their management in 241 natural and mixed World Heritage Sites from documents collated by UNESCO and the International Union for Conservation of Nature (IUCN), found that reports on the status of biological invasions were often inconsistent.The research, published in Dr Shackleton added, "Detailed information on invasive alien species management undertaken in World Heritage Sites was available for fewer than half of the sites that listed invasive alien species as a threat."There is clearly a need for an improved monitoring and reporting system for biological invasions in World Heritage Sites and likely the same for other protected areas globally."The new framework devised by the scientists, which has been tested at seven World Heritage Sites, covers collecting information and reporting on; pathways, alien species present, impacts, management, predicting future threat and management needs, the status of knowledge and gaps, and, assigning an overall 'threat score' to the protected area.Dr Witt said, "We need urgent action right now to reduce the severity of these threats that include a range of invasive alien plant species -- such as Mimosa pigra and Prosopis juliflora -- and we believe that the development of this monitoring and reporting framework is a step in the right direction to protecting areas moving forward."Based upon a previous review of invasive plants in the Serengeti-Mara ecosystem, Dr Witt added, "Failure to act could, for instance, see the devastation of the Serengeti-Mara ecosystem as we know it and that would have a major impact upon the annual wildebeest migration." Dr Jäger concurs, "Invasive mammals and invertebrates in Galápagos threaten some of the animals made famous by Darwin, such as the giant tortoise and Darwin's finches."In testing the devised framework, which categorises the level of threat posed by invasive alien species as 'very high', 'high', 'moderate' and 'low; the researchers have already yielded more information than from past monitoring initiatives.For example, the invasive alien species threat level indicated in the 2017 IUCN World Heritage Outlook for the Serengeti, Keoladeo, Doñana and the Vredefort Dome sites was 'data deficient' or 'low threat' or 'not listed', whereas all of these World Heritage Sites are now categorised as facing 'moderate' to 'high' threats from biological invasions.Co-author Prof. David Richardson said, "World Heritage Sites face growing threats from a range of biological invasions which impact upon native biodiversity and the delivery of ecosystem services. Not only that but invasive alien species are a financial burden as costs for management can be extremely high.""One key element of the new framework is listing all invasive alien species present where we can track the changes in threat or implementation of effective management over time."This is exemplified by work done on Aldabra Atoll where, according to co-author Dr Nancy Bunbury, "There has been a decrease in the number of IAS listed due to effective eradications highlighting great management success at the site over the last few years."The scientists, in their recommendations, also suggest that funding should be made available to conduct surveys at all under-resourced World Heritage Sites, to inform the reactive 'state of conservation' assessments undertaken by UNESCO and IUCN, and that monitoring could also be enhanced by members of the public as part of a series of 'citizen science' projects.
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Animals
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September 1, 2020
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https://www.sciencedaily.com/releases/2020/09/200901093415.htm
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Uncovering the hidden life of 'dead' coral reefs
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'Dead' coral rubble can support more animals than live coral, according to University of Queensland researchers trialling a high-tech sampling method.
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UQ's Dr Kenny Wolfe said that reef rubble habitat was often overlooked as desolate, unattractive and 'dead', however reef rubble was very much alive."When people think of coral reefs they often think of larger invertebrates that are easily found, such as sea cucumbers, starfish and giant clams," Dr Wolfe said."But interestingly, dead coral rubble supports more of what we call 'cryptic' animals than live coral."Cryptic animals are simply hidden creatures, that include tiny crabs, fishes, snails and worms -- all of which hide in the nooks and crannies of the reef to avoid predation."And just like on land with small insects and bugs, biodiversity in the sea can be dominated by these tiny invertebrates."As these creatures try to remain hidden, finding and surveying them requires particular care and attention.Dr Wolfe teamed up with UQ Innovate to design 3D-printed coral stacks called RUBS (RUbble Biodiversity Samplers), to survey cryptic animals on coral reefs.The 3D-printed 'coral' mimics the surrounding reef rubble, seamlessly inviting hidden reef organisms to be unknowingly monitored."Every piece of coral or rubble is different," Dr Wolfe said."RUBS provide a uniform method to survey the hidden majority on coral reefs."By sampling the RUBS' structures over time, the team were able to identify changes in the cryptic population, adding pieces to the puzzle and filling in the unknowns of coral reef food webs."This data fills important knowledge gaps, such as how small cryptic animals support coral reefs from the bottom of the food chain, all the way up to bigger predators."Dr Wolfe believes that the new technique is another step in better understanding our precious reefs -- whether considered 'alive' or 'dead'."We're really pulling back the curtain on just how alive these 'degraded' reefs are," he said."These are important habitats, which support coral reef biodiversity and important food webs."This new technology is a new opportunity for reef management, particularly for reef education and awareness."We're excited to learn about and celebrate the diversity of life in this misunderstood habitat."It was a collaboration between UQ's School of Biological Sciences and the ARC Centre of Excellence for Coral Reef Studies.
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Animals
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August 31, 2020
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https://www.sciencedaily.com/releases/2020/08/200831112356.htm
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Following African elephant trails to approach conservation differently
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Elephant trails may lead the way to better conservation approaches.
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"Think of elephants as engineers of the forests," said Melissa J. Remis, professor and head of anthropology at Purdue University, who is best known for her work in ecology and behavior of western gorillas and their ecosystems. "Elephants shape the landscape in many ways that benefit humans. We're talking thousands of miles of trails. If we think about the loss of elephants over time, then we will see the forest structure change and human activities also would shift."These massive creatures trample thick vegetation through dense forests in the Central African Republic's Congo Basin as they move from the forests' fruit trees to more open water sources where they hydrate, bathe and socialize. African forest elephants, highly sociable animals, travel in small family groups to meet others at these muddy water sources, which are full of rich minerals that they can't find in the forests. By clearing routes to these destinations, elephants have created a very complex network of roads that residents, tourists, scientists and loggers still use today. If elephant populations decline, the forest grows over the trails."The fabric and way of life of local communities, and even for the industries and conservation organizations that exist in African forests, have largely been shaped by elephant landscape design," said Carolyn A. Jost Robinson, a former Purdue doctoral student and current visiting scholar who also is director of sociocultural research and engagement at the nonprofit Chengeta Wildlife. "People rely on these elephant highways, and they also are invaluable at understanding and explaining the networks."Remis and Jost Robinson focus on these massive trail networks and the ecosystem and local foraging community, called the BaAka, as they evaluate how biological anthropology plays a role in conservation. Their research is specific to the elephant trails leading to Dzanga Saline, a famous forest clearing with a large water source in the Congo area. Their findings are published online in American Anthropologist."Anthropologists are very famous for critiquing conservation but not always for coming up with effective solutions," Remis said. "The area of conservation is dominated by biological sciences, and you can't make change just tending to ecosystems. Conservation messages focus on flagship species, like elephants, and rarely do they consider the knowledge or needs of people relying on or living with those species. Attention on both could help further conservation and human rights issues."More than 30 years ago, Purdue University's Melissa Remis visited the Dzanga-Sangha Protected Areas for the first time as a biological anthropologist to study gorillas. She became known as the gorilla lady as she visited the site dozens of times. Her fieldwork showed her that to know and study the gorillas, she had to learn about the forest and other wildlife from the local residents who share the land for food, shelter and medicines. Now Remis' work focuses on the big picture -- how the effects of conservation affect people, and what role biological anthropology can play."We're broadening the conversation about conservation," said Jost Robinson, who became known as the child of the gorilla lady by local residents at their African research site. "When you see a picture in a magazine story about ivory trafficking and elephant hunting, it is unlikely that the article will capture the entire experience of the community, as well as tourists, researchers and companies with local interests. As part of this change -- whether you want to talk about climate change, forest access or wildlife protection -- these relationships have evolved and taken on new shapes. We looked back on years of data and stories and realized there was a story to tell."By focusing on the local BaAka community, especially the hunters known as tuma, the scientists capture information from local residents about interaction and living with elephants that is usually not a part of conservation plans."We want this to be a model for showing how to get additional insights when addressing how to conserve forests in better collaboration with those people who rely on them for cultural and material sustenance," Remis said. "Being able to tell their stories and share their deep knowledge about the area, and what closing off an elephant trail or part of the forest can due to cut off access to food, medicines or social networks, is usually not part of the conservation approach. We need to hear the BaAka in their own words."
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Animals
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August 31, 2020
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https://www.sciencedaily.com/releases/2020/08/200831112321.htm
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Serengeti leopard population densities healthy but vary seasonally, study finds
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A study of camera-trap data from Serengeti National Park in Tanzania found that leopard population densities in the 3.7-million-acre park are similar to those in other protected areas but vary between wet and dry seasons. The fluctuations appear to be driven by the abundance of prey and how this affects interactions with other large carnivores like lions, researchers report.
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Despite the long history of wildlife research in the Serengeti, this is the first peer-reviewed study of leopard densities in the park, said Max Allen, a carnivore ecologist with the Illinois Natural History Survey at the University of Illinois, Urbana Champaign who led the research. Allen and his team analyzed data from Snapshot Serengeti, a large collaborative effort that uses hundreds of camera traps to collect data on large cats and other wildlife in the Serengeti. The team published the new findings in the journal "In the wet season, when potential prey species like Thomson's gazelle and impala are available in abundance, leopards appear at higher densities," Allen said. "In the dry season, leopards seem to work harder to avoid other large carnivores that compete with them for less abundant food."The team used advanced analytical techniques called Bayesian statistics to estimate leopard densities for each camera-trap site and for the study area overall."We found 5.72 and 5.41 leopards per 100-square-kilometers in the wet and dry seasons, respectively," Allen said. "These densities suggest the leopard populations are at moderately healthy levels in the Serengeti. This reflects the importance of large conservation areas for large carnivores, as leopard populations are generally declining across their range."The results also highlight the importance of citizen-scientist projects for the conservation of wild species, Allen said. Snapshot Africa is one of the most effective citizen science projects in the world, he said."Large carnivores at the top of the food chain play important roles in ecosystem regulation, and disease and population control," Allen said. "The human-induced changes to habitat availability and quality are accelerating the decline of large carnivores, which are already vulnerable because they have naturally low population densities at birth."Understanding how carnivore populations are faring and what factors contribute to their success is essential to conserving them and the other wildlife in their ecosystem, Allen said. Capturing data about their habits through unobtrusive camera traps can lead to better management of the wild areas on which they depend.The INHS is a division of the Prairie Research Institute at the U. of I. The INHS, U. of I. and Slovenian Research Agency supported this research.
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August 31, 2020
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https://www.sciencedaily.com/releases/2020/08/200831094725.htm
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Hots dogs, chicken wings and city living helped wetland wood storks thrive
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Natural wetlands continue to disappear due to city and human development and are being replaced with humanmade swales, ponds and canals. This degradation and replacement of natural wetlands suggest that urban areas may be imperative to wetland species, especially when natural conditions are unpredictable. Wetland birds are often seen in and around cities; however, they have been largely ignored in urban wildlife studies. In their historic ranges, wetland birds inhabit dynamic marshes, traveling long distances to locate food. Yet, does their ability to forage for food in natural environments translate to their ability to do so in an urban environment?
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Using the Wood Stork (Mycteria americana), a large American wading bird found throughout southeastern swamps and wetlands, scientists from Florida Atlantic University's Charles E. Schmidt College of Science compared city storks with natural wetland storks to gauge their success in urban environments based on their diet and food opportunities.Results of the study, published in For the study, researchers sampled 160 nests during the 2015-2017 nesting seasons. Of the 160 sampled nests, 106 nests were in three urban colonies and 54 nests were in two natural wetland colonies in South Florida where a vast freshwater wetland, the Everglades, is located adjacent to a large urban area. They compared urban and natural wetland storks' productivity, body condition, reproductive performance, breadth of diet, and tested whether stork diets changed during suboptimal natural wetland conditions.They found that storks were able to exploit urban areas when natural food resources were scarce. This ability to switch between habitats and thus resources allowed for better reproductive performance during periods of low natural food availability. Furthermore, body condition did not differ significantly between urban and natural wetland nesting birds during either optimal or suboptimal conditions, suggesting that supplemental environmental resources do not negatively impact body condition. These findings indicate that urban areas can buffer a species from the unpredictability of natural food resources."During suboptimal conditions, urban birds expanded their diets to include more prey types, including anthropogenic food, suggesting that urban birds were able to exploit urban areas during low natural wetland prey availability," said Betsy A. Evans, Ph.D., a natural resources specialist with the United States Army Corps of Engineers and lead author, who conducted the study as a graduate student in FAU's Department of Biological Sciences with co-author Dale E. Gawlik, Ph.D., a professor in biology and FAU's Environmental Science Program. "The ability of urban birds to switch their diet to include different prey types such as human-provided food that included chicken wings and hot dogs likely allowed them to produce more chicks during poor natural wetland prey availability conditions than their non-urban counterparts."Evans and Gawlik discovered that not only were urban storks able to access human-provided food such as trash, but they also increased the proportion of amphibians such as frogs in their diet when natural wetland conditions were suboptimal. Larval frogs (tadpoles) occur in a wide range of wetland types in the study region; however, they were 10 times more abundant in roadside created wetlands such as swales, ponds and canals than in natural wetlands during the time-period of this study. This suggests that storks may also have been accessing created wetlands along roadways during suboptimal natural wetland conditions."Behavioral flexibility and the ability to travel long distances and exploit resources in dynamic systems may give wetland birds an ecological advantage in urban environments," said Gawlik. "Our findings demonstrated that urban storks expanded their diets during times of low natural wetland prey availability to include resources commonly found in urban areas, partially dampening the natural wetland food limitation on wading bird populations. Natural wetland birds, however, paid a greater reproductive penalty during suboptimal conditions than their urban counterparts. Furthermore, this ability to switch diets between resource pulses may reduce population fluctuations and lower the risk of extinction."The study demonstrates that urban environments may support biodiversity in a variety of ways. To mitigate potential threats from urbanization it will be important to understand how species exploit new resources as well as how they are affected by loss of resources from human activities.For the study, the researchers visited two natural wetland colonies and three urban colonies one to two times per week during the 2015-2017 breeding seasons (approximately March through June). They selected these study colonies based on their range of hydrological conditions and history of repeated use by nesting storks. They describe colony landscape type broadly as either "urban" or "natural wetland" with natural wetland colonies occurring within Everglades National Park and urban colonies occurring within the urban east coast corridor of South Florida. At each colony location, they marked individual nests from which they collected productivity, body condition, and diet information.This research was partially supported by the Florida Department of Transportation (BDV27-922-02).
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Animals
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August 28, 2020
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https://www.sciencedaily.com/releases/2020/08/200828102149.htm
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The northern quoll: An amazingly versatile survivor?
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The northern quoll, one of Australia's most adorable and endangered native carnivores, appears to be adapted to dramatically different landscapes -- which may be key to the species' survival.
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University of Queensland PhD candidate Pietro Viacava co-led a study that found similarities between northern quoll skulls across a 5000 kilometre range, which has raised hopes scientists will be able to cross-breed isolated populations."Northern quolls are in danger -- a lot has been thrown at them," Mr Viacava said."They've been victims of a devastating cane toad invasion, increases in bushfires and habitat fragmentation, all while facing stiff competition from other carnivores such as dingoes and cats."The problem we are facing with conserving the northern quoll is that there may be too little genetic diversity in these handful of remaining populations, scattered across Australia."If we cross-bred them, we might run the risk that they wouldn't be ideally suited to these diverse environments."Their skulls, for example, might not be properly adapted to eat local prey, as it differs across Australia."Luckily, this doesn't seem to be the case -- these quolls seem to be incredibly versatile."The research team used a technique known as 'geometric morphometrics' to characterise skull shape variation in museum specimens of northern quolls.They looked for shape differences between populations, or whether environmental conditions coincided with changes in skull shape.Dr Vera Weisbecker from the Flinders University College of Science and Engineering supervised the study, and said the results appeared to be a win for northern quoll conservation."Quoll skull shapes were mostly similar across their entire range, although the shapes did vary with the size of the animals," Dr Weisbecker said."This means, for example, that a quoll skull from Pilbara region in WA looked nearly the same as a similar-sized one from south-eastern Queensland, 5000 kilometres apart."Although other parts of the animal's body and genetic factors need to be considered, we will most likely be able to breed animals from different populations for conservation without losing adaptations to feeding."However, there is also a much less positive potential explanation for the results."Scientists have long suspected that marsupial mammals -- such as quolls, kangaroos and koalas -- are seriously limited in the degree to which they can adapt their skull and skeleton," Dr Weisbecker said."This is because newborn marsupials require a specifically shaped snout to be able to latch onto the mother's teat."In that case, what we see may actually be a serious limitation on the ability of quolls to adapt, rather than the much more hopeful multipurpose solution we propose."To further explore this possibility, the team is now looking at how closely related species of antechinus -- smaller quoll relatives -- differ in skull shape.The team includes researchers from UQ, Flinders University, Queensland University of Technology and the University of New England, with funding from the Australian Research Council.
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Animals
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August 27, 2020
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https://www.sciencedaily.com/releases/2020/08/200827141305.htm
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Early Cambrian fossil: Bizarre half-billion-year-old worm with tentacles solves evolutionary mystery
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New research undertaken by scientists at the Smithsonian National Museum of Natural History, Royal Ontario Museum (ROM) and University of Montreal, has uncovered fossils of a new species of marine animal,
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With the early evolution of hemichordates being contentious among researchers the discovery of Although enteropneusts and pterobranchs appear to be quite different types of animals they are closely related. This close relationship is supported by DNA analysis of present-day species. More broadly, the role of The enteropneusta are a group of animals known commonly as acorn worms, which are long, mostly mud-burrowing animals, that can be found today in oceans around the world from the tropics to Antarctic. The other main group of animals within hemichordates are pterobranchs, which are microscopic animals that live in colonies, each protected by tubes they construct and which feed on plankton using a crown of tentacled arms."Acorn worms and pterobranchs look so different from each other that understanding the origins of their evolutionary relationship has been a major historical question in zoology," said Dr. Karma Nanglu, Peter Buck Deep Time post-doctoral fellow at the Smithsonian National Museum of Natural History and lead author on this paper. "Answering this question has been made much harder by the extreme lack of fossils of these soft-bodied hemichordates. Throughout the half-billion-year-long history of hemichordates you can count on one hand the number of exceptional preserved fossil species."Despite being just two centimeters in length, the remarkably preserved soft tissues of the "An ancient animal with an intermediary anatomy between acorn worms and pterobranchs had been hypothesized before but this new animal is the clearest view of what the ancestral hemichordate may have looked like," says Dr. Christopher Cameron, Associate Professor at the University of Montreal and a co-author on this study. "It's exciting to have so many new anatomical details to help drive new hypotheses about hemichordate evolution."In the case of "The Burgess Shale has been pivotal in understanding early animal evolution since its discovery over 100 years ago," says co-author Dr. Jean-Bernard Caron, Richard M. Ivey Curator of Invertebrate Palaeontology at the ROM and Associate Professor at the University of Toronto. Dr. Caron led the field expedition in 2010 which collected the 33 fossils of "In most localities, you would be lucky to have the hardest parts of animals, like bones and teeth, preserved, but at the Burgess Shale even the softest body parts can be fossilized in exquisite detail," says Dr. Caron. "This new species underscores the importance of making new fossil discoveries to shine light on the most stubborn evolutionary mysteries."In this particular case, Hemichordates belong to a major division of animal life called Deuterostomia, which includes chordates like fish and mammals, and not the division of animal life called Protostomia, that includes arthropods such as insects and annelids such as earthworms. Dr. Nanglu explains, when looking at "The close relationship between hemichordates and our own evolutionary group, the chordates, is one of the first things that made me excited to research them," Nanglu explains. "Understanding the ancient connections that join animals like fish and even humans to their distant cousins like sea urchins and acorn worms is such an interesting area on the evolutionary tree and The original 1909 discovery and research about the Burgess Shale was made by Charles Walcott, who was Secretary of the Smithsonian Institution at the time. The Burgess Shale fossil sites are located within Yoho and Kootenay National Parks and are managed by Parks Canada.
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Animals
| 2,020 |
August 27, 2020
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https://www.sciencedaily.com/releases/2020/08/200827102144.htm
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Call of the wild: Individual dolphin calls used to estimate population size and movement
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An international team of scientists has succeeded in using the signature whistles of individual bottlenose dolphins to estimate the size of the population and track their movement.
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The research, led by Stellenbosch University and the University of Plymouth, marks the first time that acoustic monitoring has been used in place of photographs to generate abundance estimates of dolphin populations.Writing in the They are now working to refine the technique, in the hope it can be used to track other species -- with a current focus on endangered species such as humpback dolphins.Quicker information processing and advances in statistical analysis mean in the future that automated detection of individually distinctive calls could be possible. This can generate important information on individual animals and would be particularly useful for small, threatened populations where every individual counts."The capture-recapture of individually distinctive signature whistles has not been attempted before," says the paper's senior author Dr Tess Gridley, Co-Director of Sea Search and the Namibian Dolphin Project and a postdoctoral fellow in the Department of Botany and Zoology at SU. "The dolphins use these sounds throughout life and each has its own unique whistle. Therefore, by recording signature whistles over time and in different places we can calculate where animals are moving to and how many animals there are in a population."Working with Dr Simon Elwen of Stellenbosch University, the Namibian Dolphin Project has been researching Namibia's resident bottlenose dolphins for the past 12 years, and built up a catalogue of more than 55 signature whistles dating back to 2009.This particular study was led by Emma Longden, who began the project during her BSc (Hons) Marine Biology degree at the University of Plymouth. As an undergraduate, Emma completed an internship with the Namibia Dolphin Project for a month in 2016, and returned again in 2018 to complete work on the mark-recapture project.She analysed more than 4000 hours of acoustic data from four hydrophones positioned along the coast south and north of Walvis Bay, Namibia, during the first six months of 2016.All in all, they identified 204 acoustic encounters, 50 of which contained signature whistle types. From these encounters, 53 signature whistle types were identified; 40 were in an existing catalogue developed in 2014 for the Walvis Bay bottlenose dolphin population, and 13 were newly identified. Of the 53 signature whistle types identified, 43% were captured only once, whereas the majority (57%) were recaptured twice or more."One of the great things about bioacoustics is that you can leave a hydrophone in the water for weeks at a time and collect so much data without interfering with the lives of the animals you are studying," says Emma, whose work on the project was also supervised by Dr Clare Embling, Associate Professor of Marine Ecology at the University of Plymouth.Dr Embling added: "This work is incredibly important as it allows us to track and count the number of dolphins in small vulnerable populations. It builds on our previous research looking at the impacts of noise on marine organisms and monitoring vulnerable marine mammal populations. It also showcases the fantastic level of research that our marine biology students are able to achieve, and the opportunities available to them through our partnerships with conservation organisations such as the Namibia Dolphin Project and the Ocean Giants Trust."Future research includes the work undertaken by PhD student Sasha Dines from Stellenbosch University to further refine the technique to better understand the population of endangered humpback dolphins in South Africa. Another PhD student, Jack Fearey from the University of Cape Town, is continuing to conduct research along the Namibian Coast.
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Animals
| 2,020 |
August 27, 2020
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https://www.sciencedaily.com/releases/2020/08/200827101826.htm
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Daylight study reveals how animals adapt between seasons
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Scientists have discovered how a biological switch helps animals make the seasonal changes crucial for survival, such as growing a warm winter coat and adjusting body temperatures.
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The findings reveal how the brain responds to short and long days to allow animals to adapt to changing conditions and governs vital behaviour such as breeding cycles.Researchers say the study in sheep could help explain the timings of seasonal adaptations in a number of species such as birds, reptiles and mammals.The body's internal clock choreographs cycles in hormone levels and affects traits such as sleep and hunger. These alter over the course of the day -- known as circadian rhythms -- and are influenced by genetics.Similar rhythms are also seen seasonally, but until now it was unclear how genes play a role in the biological changes that fluctuate between winter and summer.Researchers led by the Universities of Edinburgh and Manchester studied an endocrine gland attached to the brain called the pituitary gland in sheep experiencing short or long lengths of day.Brain tissue was analysed for gene activity across time, allowing scientists to observe the biological processes that happen in response to different day lengths.They found that one of two possible biological mechanisms is activated within the pituitary gland depending on whether the day is long or short.In summer when nights are long, the brain generates hormones that cause a cascade of gene activity leading to biological characteristics associated with summer.When nights are short in winter, the switch is flipped -- night-time hormones are released for longer, triggering biological processes linked to winter.The study found that in the sheep brain, both processes involve a circadian gene known as BMAL2, which is found in many animals but whose role in the seasonal clock was previously unknown.The study, published in The Roslin Institute receives strategic investment funding from the Biotechnology and Biological Sciences Research Council and it is part of the University of Edinburgh's Royal (Dick) School of Veterinary Studies.Professor Simone Meddle, who co-led the research from the University of Edinburgh's Roslin Institute, said: "Fluctuations in hormones and behaviour are part of a delicate biological orchestra that is crucial to life. Many animals depend on seasonal changes in their biology to survive and our findings are a crucial part of the puzzle to understand the underlying processes."Professor Andrew Loudon, who co-led the study from the University of Manchester, said: "The genetic 'flip-flop' timer we have identified is key to functions such as fertility as sheep transition between winter and summer. We speculate that this genetic timer is likely to be fundamental to yearly changes in many species."
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Animals
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August 27, 2020
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https://www.sciencedaily.com/releases/2020/08/200827101819.htm
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First complete dinosaur skeleton ever found is ready for its closeup at last
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The first complete dinosaur skeleton ever identified has finally been studied in detail and found its place in the dinosaur family tree, completing a project that began more than a century and a half ago.
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The skeleton of this dinosaur, called Scelidosaurus, was collected more than 160 years ago on west Dorset's Jurassic Coast. The rocks in which it was fossilised are around 193 million years old, close to the dawn of the Age of Dinosaurs.This remarkable specimen -- the first complete dinosaur skeleton ever recovered -- was sent to Richard Owen at the British Museum, the man who invented the word dinosaur.So, what did Owen do with this find? He published two short papers on its anatomy, but many details were left unrecorded. Owen did not reconstruct the animal as it might have appeared in life and made no attempt to understand its relationship to other known dinosaurs of the time. In short, he 're-buried' it in the literature of the time, and so it has remained ever since: known, yet obscure and misunderstood.Over the past three years, Dr David Norman from Cambridge's Department of Earth Sciences has been working to finish the work which Owen started, preparing a detailed description and biological analysis of the skeleton of Scelidosaurus, the original of which is stored at the Natural History Museum in London, with other specimens at Bristol City Museum and the Sedgwick Museum, Cambridge.The results of Norman's work, published as four separate studies in the For more than a century, dinosaurs were primarily classified according to the shape of their hip bones: they were either saurischians ('lizard-hipped') or ornithischians ('bird-hipped').However, in 2017, Norman and his former PhD students Matthew Baron and Paul Barrett argued that these dinosaur family groupings needed to be rearranged, re-defined and re-named. In a study published in Nature, the researchers suggested that bird-hipped dinosaurs and lizard-hipped dinosaurs such as Tyrannosaurus evolved from a common ancestor, potentially overturning more than a century of theory about the evolutionary history of dinosaurs.Another fact that emerged from their work on dinosaur relationships was that the earliest known ornithischians first appeared in the Early Jurassic Period. "Scelidosaurus is just such a dinosaur and represents a species that appeared at, or close to, the evolutionary 'birth' of the Ornithischia," said Norman, who is a Fellow of Christ's College, Cambridge. "Given that context, what was actually known of Scelidosaurus? The answer is remarkably little!"Norman has now completed a study of all known material attributable to Scelidosaurus and his research has revealed many firsts."Nobody knew that the skull had horns on its back edge," said Norman. "It had several bones that have never been recognised in any other dinosaur. It's also clear from the rough texturing of the skull bones that it was, in life, covered by hardened horny scutes, a little bit like the scutes on the surface of the skulls of living turtles. In fact, its entire body was protected by skin that anchored an array of stud-like bony spikes and plates."Now that its anatomy is understood, it is possible to examine where Scelidosaurus sits in the dinosaur family tree. It had been regarded for many decades as an early member of the group that included the stegosaurs, including Stegosaurus with its huge bony plates along its spine and a spiky tail, and ankylosaurs, the armour-plated 'tanks' of the dinosaur era, but that was based on a poor understanding of the anatomy of Scelidosaurus. Now it seems that Scelidosaurus is an ancestor of the ankylosaurs alone."It is unfortunate that such an important dinosaur, discovered at such a critical time in the early study of dinosaurs, was never properly described," said Norman. "It has now -- at last! -- been described in detail and provides many new and unexpected insights concerning the biology of early dinosaurs and their underlying relationships. It seems a shame that the work was not done earlier but, as they say, better late than never."
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Animals
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August 26, 2020
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https://www.sciencedaily.com/releases/2020/08/200826200704.htm
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Using math to examine the sex differences in dinosaurs
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Male lions typically have manes. Male peacocks have six-foot-long tail feathers. Female eagles and hawks can be about 30% bigger than males. But if you only had these animals' fossils to go off of, it would be hard to confidently say that those differences were because of the animals' sex. That's the problem that paleontologists face: it's hard to tell if dinosaurs with different features were separate species, different ages, males and females of the same species, or just varied in a way that had nothing to do with sex. A lot of the work trying to show differences between male and female dinosaurs has come back inconclusive. But in a new paper, scientists show how using a different kind of statistical analysis can often estimate the degree of sexual variation in a dataset of fossils.
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"It's a whole new way of looking at fossils and judging the likelihood that the traits we see correlate with sex," says Evan Saitta, a research associate at Chicago's Field Museum and the lead author of the new paper in the Unless you find a dinosaur skeleton that contains the fossilized eggs that it was about to lay, or a similar dead giveaway, it's hard to be sure about an individual dinosaur's sex. But many birds, the only living dinosaurs, vary a lot between males and females on average, a phenomenon called sexual dimorphism. Dinosaurs' cousins, the crocodilians, show sexual dimorphism too. So it stands to reason that in many species of dinosaurs, males and females would differ from each other in a variety of traits.But not all differences in animals of the same species are linked to their sex. For example, in humans, average height is related to sex, but other traits like eye color and hair color don't neatly map onto men versus women. We often don't know precisely how the traits we see in dinosaurs relate to their sex, either. Since we don't know if, say, larger dinosaurs were female, or dinosaurs with bigger crests on their heads were male, Saitta and his colleagues looked for patterns in the differences between individuals of the same species. To do that, they examined measurements from a bunch of fossils and modern species and did a lot of math.Other paleontologists have tried to look for sexual dimorphism in dinosaurs using a form of statistics (called significance testing, for all you stats nerds) where you collect all your data points and then calculate the probability that those results could have happened by pure chance rather than an actual cause (like how doctors determine whether a new medicine is more helpful than a placebo). This kind of analysis sometimes works for big, clean datasets. But, says Saitta, "with a lot of these dinosaur tests, our data is pretty bad" -- there aren't that many fossil specimens, or they're incomplete or poorly preserved. Using significance testing in these cases, Saitta argues, results in a lot of false negatives: since the samples are small, it takes an extreme amount of variation between the sexes to trigger a positive test result. (Significance testing isn't just a consideration for paleontologists -- concerns over a "replication crisis" have plagued researchers in psychology and medicine, where certain studies are difficult to reproduce.)Instead, Saitta and his colleagues experimented with another form of stats, called effect size statistics. Effect size statistics is better for smaller datasets because it attempts to estimate the degree of sex differences and calculate the uncertainty in that estimate. This alternative statistical method takes natural variations into account without viewing dimorphism as black-or-white-many sexual dimorphisms can be subtle. Co-author Max Stockdale of the University of Bristol wrote the code to run the statistical simulations. Saitta and his colleagues uploaded measurements of dinosaur fossils to the program, and it yielded estimates of body mass dimorphism and error bars in those estimates that would have simply been dismissed using significance testing."We showed that if you adopt this paradigm shift in statistics, where you attempt to estimate the magnitude of an effect and then put error bars around that, you can often produce a fairly accurate estimate of sexual variation even when the sexes of the individuals are unknown," says Saitta.For instance, Saitta and his colleagues found that in the dinosaur Maiasaura, adult specimens vary a lot in size, and the analyses show that these are likelier to correspond to sexual variation than differences seen in other dinosaur species. But while the current data suggest that one sex was about 45% bigger than the other, they can't tell if the bigger ones are males or females.While there's a lot of work yet to be done, Saitta says he's excited that the statistical simulations gave such consistent results despite the limits of the fossil data."Sexual selection is such an important driver of evolution, and to limit ourselves to ineffective statistical approaches hurts our ability to understand the paleobiology of these animals," he says. "We need to account for sexual variation in the fossil record.""I'm happy to play a small part in this sort of statistical revolution," he adds. "Effect size statistics has a major impact for psychological and medical research, so to apply it to dinosaurs and paleontology is really cool."
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Animals
| 2,020 |
August 26, 2020
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https://www.sciencedaily.com/releases/2020/08/200826101619.htm
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Domesticated chickens have smaller brains
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Researchers from Linköping University suggest a process by which the timid junglefowl from the rain forest could have become today's domesticated chicken. When the scientists selectively bred the junglefowl with least fear of humans for 10 generations, the offspring acquired smaller brains and found it easier to become accustomed to frightening but non-hazardous events. The results shed new light over how domestication may have changed animals so much in a relatively short time.
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Chickens are the most common birds on Earth. There are currently more than 20 billion individuals on the planet. All of them have come from the Red Junglefowl, originally found in south-east Asia. This species was tamed and domesticated by humans approximately 10,000 years ago. The results of the current study show that when our ancestors selected the tamest individuals for breeding, they may at the same time have unconsciously selected birds with a different brain -- one that may have been more suitable for a life among humans. The findings are published in Researchers Rebecca Katajamaa and Per Jensen started with a group of wild Red Junglefowl and selected as parents the birds that showed least fear of humans in a standard test. The breeding experiment was conducted for 10 generations. The birds that showed greatest fear of humans were placed into a second group. The researchers believe that they have in this way imitated the factor that must have been the most important during early domestication, namely that it was possible to tame the animals.A somewhat unexpected result of the breeding was that the brains of the domesticated birds gradually became smaller relative to body size, which mirrors what has happened to modern domesticated chickens during the domestication process. The change was particularly pronounced in the brain stem, a primitive part of the brain that is involved in, among other things, certain stress reactions. The brain stem was relatively smaller in animals that were not overly timid.The scientists carried out two behavioural experiments, to determine whether the difference in brain size and composition affected the ability of the fowl to learn. One test investigated how rapidly the birds became accustomed to something that could be experienced as frightening, but which was actually non-hazardous, in this case a flashing light. The tame birds became accustomed and stopped reacting to the stimulus significantly more rapidly."We believe that the ability to become accustomed rapidly is beneficial for the birds that are to live among humans, where events that are unknown and frightening, but not dangerous, are part of everyday life," says Rebecca Katajamaa, doctoral student in the Department of Physics, Chemistry and Biology at Linköping University.The researchers also investigated whether the birds differed in the ability to learn to associate two things with each other, such as coupling a certain pattern with food. This process is known as "associative learning." However, they found no differences between the two groups.It is not possible to say whether the differences in behaviour shown in the study are directly connected with the differences in brain size and composition. The researchers plan to investigate this in more detail."Our study not only sheds light on a possible process by which chickens -- and possibly other species -- become domesticated. It may also give new insight into how the structure of the brain is connected with differences in behaviour between individuals and species," says Per Jensen, professor in the Department of Physics, Chemistry and Biology at Linköping University.The research has received financial support from the Swedish Research Council.
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Animals
| 2,020 |
August 26, 2020
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https://www.sciencedaily.com/releases/2020/08/200819094800.htm
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Mother bats use baby talk to communicate with their pups
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When talking to babies, humans slow down their speech, raise their pitch and change the "color" of their voice. This "baby talk," as people know it, increases the infant's attention and facilitates language learning. Among animals, mothers often engage in pup-directed vocalizations too, but does this also imply voice changes? A team of scientists that included Smithsonian Tropical Research Institute (STRI) researchers explored whether infant-directed communication in bats resulted in vocalization changes.
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They focused on the greater sac-winged bat During their first three months of life, as Much like human "baby talk," the pup-directed vocalizations of adult females presented a different "color" and pitch than the calls directed towards other adult bats. Male bats also communicated with the pups, but in a way that seemed to transmit the "vocal signature" of their social group."Pup isolation calls are acoustically more similar to those of males from the same social group than to those of other males," said Mirjam Knörnschild, STRI research associate and co-author of the paper. "These results suggest that adult male vocalizations may serve as guidance for the development of group signatures in pup calls."This is the first time that scientists describe a phenomenon that could resemble "baby talk" among bats, indicating that parent-offspring communication in bats is more complex than previously thought and opening new avenues for further research."These results show that social feedback is important during vocal development, not only in humans but also in other vocal-learning species like
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Animals
| 2,020 |
August 25, 2020
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https://www.sciencedaily.com/releases/2020/08/200825121829.htm
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Importance of rainfall highlighted for tropical animals
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Imagine a tropical forest and you might conjure up tall trees hung with vines, brightly colored birds, howling monkeys, and ... rain. Indeed, precipitation patterns, along with temperature, dictate where tropical forests are distributed around the world, but surprisingly, scientists know very little about the direct effects of rainfall on animals.
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A new conceptual framework, developed by University of Illinois and Kansas State University researchers, calls for the scientific community to formally consider the role of precipitation in an organism's ecological niche -- the set of biological and environmental factors that optimize life for a given critter."We understand exactly how most animals respond to temperature, but the same is not true for rain," says Alice Boyle, associate professor in the Division of Biology at Kansas State and lead author on the In the article, Boyle and co-authors Elsie Shogren and Jeff Brawn propose and define what they call the hygric niche: the collection of physiological, behavioral, and ecological processes and interactions predicting how endothermic, or warm-blooded, organisms perform under a given precipitation scenario."Prior to this, there was no unifying conceptual framework to understand why responses to precipitation might differ between species or even within the same species, depending on the location of the study," Boyle says. "We've heard from scientists who have said, 'Wow, how come I've never thought about this before?' I think this new framework is probably going to change the way many people study the distributions, physiology, and demographic responses of endotherms."Brawn, professor in the Department of Natural Resources and Environmental Sciences at Illinois, adds, "This concept has implications for conservation of sensitive organisms, long term. In terms of planning where to invest conservation dollars or where to prioritize habitat, we should be looking at rainfall refugia where precipitation regimes are likely to stay intact over time."Because the effects of temperature and moisture are so difficult to disentangle, the team developed the concept of the hygric niche using decades of bird and mammal research from the tropics. Temperature in these equatorial landscapes varies little on an annual basis, but rainfall can vary widely, with some locations experiencing distinct dry and wet seasons and others experiencing daily precipitation throughout the year. But unfortunately, in many tropical locations, these millennia-old patterns are now shifting due to climate and land use change."Human-caused changes to climate are resulting in some areas getting wetter, and other areas getting drier. Also, it is not just the amount of precipitation that is changing; the timing and magnitude of storms are also changing, and we have very little idea of how any of this will affect animals," according to the authors.In their article, Brawn and Boyle describe ways in which precipitation (too little or too much) can affect organisms at the individual, population, and community levels. While rain clearly affects food supply, it also can affect foraging behavior, reproductive and population growth rates, and competitive interactions in subtle ways that might be difficult for researchers to trace back to any particular source. And even small shifts in tropical rainfall patterns could have large effects."Even if you can see intact forest out to the horizon, if the precipitation regimes change, the integrity of that ecosystem may be compromised. And that's concerning," Brawn says.Although the concept was conceived with tropical systems in mind, the researchers suggest it can and should be applied to ecosystems and organisms outside the tropics, with a bit of tweaking and further study."I work in both tropical and grassland systems and my major focus of research in grassland birds, one of the most threatened group of birds in North America, is understanding how temporal variation in precipitation affects those populations. So the questions and the concepts are broadly applicable," Boyle says. "It's just that it was more tractable to lay them out and argue for their importance in tropical systems."Laying out a new ecological concept requires lots of testing by the research community to identify its limitations, and that's just what Boyle and Brawn hope will happen."The next steps involve the research community testing key assumptions and predictions of our model," they say. "One of the hardest but most important tasks is to understand whether rainfall affects different animal species for the same or different reasons. Is it really mostly about food, or are these less-obvious physiological costs more important than we thought? Answering these questions will be crucial to doing effective conservation and climate change mitigation in the tropics."The work was supported by the National Science Foundation (grant #1646806).The Department of Natural Resources and Environmental Sciences is in the College of Agricultural, Consumer and Environmental Sciences at the University of Illinois.
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Animals
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August 25, 2020
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https://www.sciencedaily.com/releases/2020/08/200825110740.htm
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Life in a nutshell: New species found in the carapace of late cretaceous marine turtle
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While paleontologists have a wealth of vertebrate fossils at their disposal, their knowledge of the ecology of ancient extinct species, particularly regarding their relationship with invertebrate species, is relatively poor. As bones and hard shells "fossilize" much better than soft tissues and cartilage, scientists are limited in their ability to infer the presence of parasitic or symbiotic organisms living in or on these ancient vertebrates. As a result, relatively little is known about the evolutionary relationships between these ancient "clades" and their modern descendants.
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All hope is not lost, though, as researchers can infer the presence of these small organisms from the footprints they left behind. These records are called trace fossils, or ichnofossils. One clear example of such ichnofossils is the boreholes that many mollusks make in the turtle shell remains and whale and fish bones on the ocean floor. However, to this date, there have been no indications that such species also lived in the shell while the turtle was alive and well.In their recent study published in the journal Eager to learn more about the organisms responsible for this, the scientists formulated a hypothesis, based on previous borehole evidence found on ancient marine turtle shells. After observing the fossil up close and measuring the morphological characteristics of the boreholes, they produced a 3-dimensional reconstruction of the carapace and the cross-section of one of the boreholes, which allowed them to observe the intricate details left by the species.Sato, who is the lead author of this study, elaborates on the surprising evidence they found, "We saw that there were signs of healing around the mouth of boreholes, suggesting that the turtle was alive when the organisms settled on the carapace." Based on the morphology and positioning of the boreholes, they determined that the likely culprits for these boreholes were "bivalves" from the superfamily Pholadoidea, creatures similar to the modern clams. These "sessile" (or immobile) organisms normally require a stable substrate to bore into, and the turtle carapace was a suitable host. The fact that the host animal was swimming around freely probably helped, as this allowed exposure to new environments.Sato and Jenkins identified the boreholes called Karethraichnus; however, they were unable to match the characteristics of the boreholes they found with those made by any currently described species. This only meant one thing: that they had stumbled onto a completely new species! They have accordingly named this new species as Sato is excited about the implications of their findings, stating, "This is the first study to report this unique behavior of boring bivalves as a symbiont of living marine vertebrate, which is a significant finding for the paleoecology and evolution of ancient boring bivalve clades." Previously, no such species had been shown to live on the carapace of living vertebrates. Instead, they were often reported to occur on the remains of marine turtles and other vertebrates, laying on the ocean floor alongside various decomposing organisms. By attaching themselves on a live, free-swimming substrate, such as the carapace of a marine turtle, these pholadoid bivalves may have paved the way for a novel, yet-unknown evolutionary path of accessing previously unexplored niches and diversifying into new species. As the tracemaker bivalves of
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Animals
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August 24, 2020
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https://www.sciencedaily.com/releases/2020/08/200824165608.htm
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Fossils reveal diversity of animal life roaming Europe 2 million years ago
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A re-analysis of fossils from one of Europe's most significant paleontological sites reveals a wide diversity of animal species, including a large terrestrial monkey, short-necked giraffe, rhinos and saber-toothed cats.
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These and other species roamed the open grasslands of Eastern Europe during the early Pleistocene, approximately 2 million years ago. Ultimately, the researchers hope the fossils will provide clues about how and when early humans migrated to Eurasia from Africa. Reconstructions of past environments like this also could help researchers better understand future climate change."My colleagues and I are excited to draw attention back to the fossil site of Grăunceanu and the fossil potential of the Olteţ River Valley of Romania," said Claire Terhune, associate professor of anthropology at the University of Arkansas. "It's such a diverse faunal community. We found multiple animals that hadn't been clearly identified in the area before, and many that are no longer found in Europe at all. Of course, we think these findings alone are interesting, but they also have important implications for early humans moving into the continent at that time."About 124 miles west of the Romanian capital of Bucharest, the Olteţ River Valley, including the the important site of Grăunceanu, is one of Eastern Europe's richest fossil deposits. Many Olteţ Valley fossil sites, including Grăunceanu, were discovered in the 1960s after landslides caused in part by deforestation due to increased agricultural activity in the area.Archeologists and paleontologists from the Emil Racoviţă Institute of Speleology in Bucharest excavated the sites soon after they were discovered. Fossils were recovered and stored at the institute, and scholarly publications about the sites flourished in the 1970s and 1980s. But interest in these fossils and sites waned over the past 20 to 30 years, in part because many records of the excavations and fossils were lost.Since 2012, the international team, including Terhune and researchers from Romania, the United States, Sweden and France, has focused on this important fossil region. Their work has included extensive identification of fossils at the institute and additional field work.In addition to the species mentioned above, the researchers identified fossil remains of animals similar to modern-day moose, bison, deer, horse, ostrich, pig and many others. They also identified a fossil species of pangolin, which were thought to have existed in Europe during the early Pleistocene but had not been solidly confirmed until now. Today, pangolins, which look like the combination of an armadillo and anteater and are among the most trafficked animals in the world, are found only in Asia and Africa.
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Animals
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August 24, 2020
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https://www.sciencedaily.com/releases/2020/08/200824120042.htm
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Reducing transmission risk of livestock disease
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The risk of transmitting the livestock virus PPRV, which threatens 80 percent of the world's sheep and goats, increases with certain husbandry practices but not herd size. A new study, led by researchers at Penn State, investigated how transmission of PPRV might change at different scales and identified specific husbandry practices associated with increased odds of infection -- including the introduction of sheep and goats to the herd, sheep or goat attendance at seasonal grazing camps, and the sales or gifting of goats from the herd.
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The sheep and goat plague virus, formally known as peste des petits ruminants virus (PPRV) and now known as small ruminant morbillivirus (SRMV), produces a highly infectious and often fatal disease. This study, which appears online Aug. 24 in the journal "If we can identify behaviors that increase transmission risk, we can better inform how we allocate resources to manage the virus," said Catherine Herzog, epidemiologist and Huck postdoctoral scholar at the Center for Infectious Disease Dynamics at Penn State and first author of the paper.The researchers previously found that transmission risk of PPRV was greater among herds in pastoral villages, where people rely almost solely on livestock for their livelihood, compared to herds from agropastoral villages, where people rely on a mix of livestock and agriculture. However, the factors driving these differences were unclear.Because pastoral villages typically have much larger herds than agropastoral villages, the researchers first investigated whether herd size was related to the rate at which animals become infected -- the force of infection. One might expect the rate of infection to increase with herd size, because an animal in a larger herd would have the potential to closely interact with more individuals."We hypothesized that the force of infection would increase with herd size -- a pattern known as density-dependent transmission -- but interestingly this is not what we observed," said Ottar Bjørnstad, Distinguished Professor of Entomology and Biology and J. Lloyd and Dorothy Foehr Huck Chair of Epidemiology at Penn State and a member of the research team.Instead, Bjornstad explained that at the level of an individual compound, which might contain animals from multiple households living together in a herd, the data suggest that transmission is not related to herd size -- a pattern known as frequency dependent transmission. The researchers believe this is due to the formation of social cliques, whose size is unaffected by the overall herd size."Having a clear understanding of this relationship and if it varies across geographic scales will improve how we model the disease," he said.Transmission risk, however, did increase with specific husbandry practices such as the attendance of sheep or goats at seasonal grazing camps, where many herds come to aggregate, and introduction of livestock to the herd. Introductions occur when animals are purchased from or returned home from the market after a failure to sell, or if they returned from being loaned to another herd for breeding opportunities or milk production. Transmission risk also increased when cattle or goats were recently removed from the herd, through gifting, sale, or death.The researchers hope their ongoing work will help clarify the ecological mechanisms driving PPRV transmission."Now that we have evidence that these husbandry practices are associated with higher rates of infection in the Tanzanian setting, we can take a closer look at these practices and recommend improvements or modifications that could help mitigate the transmission risk," said Herzog. "For example, we could explore quarantine procedures around the introduction of animals from sales or gifting, and the return of animals from seasonal grazing camps. We could also focus our veterinary care on settings or events where risk is the highest."
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Animals
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August 24, 2020
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https://www.sciencedaily.com/releases/2020/08/200824105914.htm
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Researchers to investigate wind power effects on bats in the Baltic Sea region
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Researchers from the Universities of Turku and Helsinki in Finland have been looking into literature about wind farm impacts on bats in several countries around the Baltic Sea (Estonia, Finland, Latvia, Lithuania, Russia and Sweden) and in the rest of Europe. They published a review on the topic.
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The results are quite straightforward: impacts of wind farms on bats in the Baltic Sea region have barely been investigated."Only a handful of reports and studies are available, and they are rarely in English. The main reasons for this lack of data are probably the small numbers of turbines in the region and the shortage of information on bats themselves," says Simon Gaultier from the University of Turku, one of the authors of the review.The authors also think it is important to not rely entirely on knowledge from the rest of Europe to study bats and wind farms in the Baltic Sea region."The climate and environmental conditions for bats are different, influencing the biology and ecology of these species, including the way they are affected by wind farms."There are also concerns about survey methods and quality, especially during the environmental impact assessment of wind farm projects. It seems that current methods are not adapted to predict the actual presence of bats on the future wind farms, let alone the impacts they are facing, such as collision risks.Turbines are more and more numerous in the Baltic Sea region, a region that plays an important role for European bats: it is crossed by numerous migrating bats during spring and autumn, but is also the home of other local resident bat species such as the Northern bat (Eptesicus nilssonii)."At some point, concerns about bat conservation will appear. Bat numbers are not increasing, contrary to wind turbines. We need to anticipate and avoid this problem. However, in order to do this, we first need more information on bats."Following this need, Gaultier started collecting new data during this summer. Using ultrasound recorders located around wind farms, Gaultier and his colleagues are looking for the possible effects turbines are having on the presence and activity of bats. Other studies have reported bats being attracted by wind turbines, others being repelled."We need to monitor bats for several years to see what is going on in Finland, but we should get a first glimpse by the end of this year," says Gaultier."In the end, we want our work to be useful for both wind power planning and bat preservation by defining high-risk areas where wind turbines should not be built or designing supplementary measures to reduce the impact of current and future wind farms," he adds.
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Animals
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August 24, 2020
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https://www.sciencedaily.com/releases/2020/08/200824092037.htm
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Pigs grow new liver in lymph nodes, study shows
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Hepatocytes -- the chief functional cells of the liver -- are natural regenerators, and the lymph nodes serve as a nurturing place where they can multiply. In a new study published online and appearing in a coming issue of the journal
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"It's all about location, location, location," said senior author Eric Lagasse, Pharm.D., Ph.D., associate professor of pathology at Pitt "If hepatocytes get in the right spot and there is a need for liver functions, they will form an ectopic liver in the lymph node."The cells of the liver normally replenish themselves, but need a healthy, nurturing environment to regenerate. However, in end-stage liver disease, the liver is bound up by scar tissue and too toxic for the cells to make a comeback."The liver is in a frenzy to regenerate," said Lagasse, who also is a member of the McGowan Institute for Regenerative Medicine and the Pittsburgh Liver Research Center. "The hepatocytes try to repair their native liver, but they can't and they die."Nearly a decade ago, Lagasse noticed that if he injected healthy liver cells into the lymph nodes of a mouse, they would flourish, forming an auxiliary liver to take over the tasks of the animals' genetically induced malfunctioning liver.But mice are small. Lagasse and colleagues needed to show that a large animal could grow a meaningful mass of secondary liver tissue to overcome liver disease.To mimic human liver disease in pigs, the researchers diverted the main blood supply from the liver, and at the same time, they removed a piece of healthy liver tissue and extracted the hepatocytes. Those liver cells were then injected into the abdominal lymph nodes of the same animal they came from.All six pigs showed a recovery of liver function, and close examination of their lymph nodes revealed not only thriving hepatocytes, but also a network of bile ducts and vasculature that spontaneously formed among the transplanted liver cells.The auxiliary livers grew bigger when the damaged tissue in the animals' native liver was more severe, indicating that the animals' bodies are maintaining an equilibrium of liver mass, rather than having runaway growth akin to cancer.These findings bolster the results of another recent study, in which Lagasse and colleagues at Mayo Clinic showed that healthy liver tissue grown in the lymph nodes of pigs with a genetic liver defect spontaneously migrated to the animals' livers, where they replaced diseased cells and cured the animals' liver disease.So, regardless of the cause of liver disease, from hepatitis to alcoholism, Lagasse expects growing auxiliary livers in the lymph nodes will help.
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Animals
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August 21, 2020
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https://www.sciencedaily.com/releases/2020/08/200821161423.htm
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Genomic analysis reveals many animal species may be vulnerable to SARS-CoV-2 infection
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Humans are not the only species facing a potential threat from SARS-CoV-2, the novel coronavirus that causes COVID-19, according to a new study from the University of California, Davis.
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An international team of scientists used genomic analysis to compare the main cellular receptor for the virus in humans -- angiotensin converting enzyme-2, or ACE2 -- in 410 different species of vertebrates, including birds, fish, amphibians, reptiles and mammals.ACE2 is normally found on many different types of cells and tissues, including epithelial cells in the nose, mouth and lungs. In humans, 25 amino acids of the ACE2 protein are important for the virus to bind and gain entry into cells.The researchers used these 25 amino acid sequences of the ACE2 protein, and modeling of its predicted protein structure together with the SARS-CoV-2 spike protein, to evaluate how many of these amino acids are found in the ACE2 protein of the different species."Animals with all 25 amino acid residues matching the human protein are predicted to be at the highest risk for contracting SARS-CoV-2 via ACE2," said Joana Damas, first author for the paper and a postdoctoral research associate at UC Davis. "The risk is predicted to decrease the more the species' ACE2 binding residues differ from humans."About 40 percent of the species potentially susceptible to SARS-CoV-2 are classified as "threatened" by the International Union for Conservation of Nature and may be especially vulnerable to human-to-animal transmission. The study was published Aug. 21 in the "The data provide an important starting point for identifying vulnerable and threatened animal populations at risk of SARS-CoV-2 infection," said Harris Lewin, lead author for the study and a distinguished professor of evolution and ecology at UC Davis. "We hope it inspires practices that protect both animal and human health during the pandemic."Several critically endangered primate species, such as the Western lowland gorilla, Sumatran orangutan and Northern white-cheeked gibbon, are predicted to be at very high risk of infection by SARS-CoV-2 via their ACE2 receptor.Other animals flagged as high risk include marine mammals such as gray whales and bottlenose dolphins, as well as Chinese hamsters.Domestic animals such as cats, cattle and sheep were found to have a medium risk, and dogs, horses and pigs were found to have low risk for ACE2 binding. How this relates to infection and disease risk needs to be determined by future studies, but for those species that have known infectivity data, the correlation is high.In documented cases of SARS-COV-2 infection in mink, cats, dogs, hamsters, lions and tigers, the virus may be using ACE2 receptors or they may use receptors other than ACE2 to gain access to host cells. Lower propensity for binding could translate to lower propensity for infection, or lower ability for the infection to spread in an animal or between animals once established.Because of the potential for animals to contract the novel coronavirus from humans, and vice versa, institutions including the National Zoo and the San Diego Zoo, which both contributed genomic material to the study, have strengthened programs to protect both animals and humans."Zoonotic diseases and how to prevent human to animal transmission is not a new challenge to zoos and animal care professionals," said co-author Klaus-Peter Koepfli, senior research scientist at Smithsonian-Mason School of Conservation and former conservation biologist with the Smithsonian Conservation Biology Institute's Center for Species Survival and Center for Conservation Genomics. "This new information allows us to focus our efforts and plan accordingly to keep animals and humans safe."The authors urge caution against overinterpreting the predicted animal risks based on the computational results, noting the actual risks can only be confirmed with additional experimental data. The list of animals can be found here.Research has shown that the immediate ancestor of SARS-CoV-2 likely originated in a species of bat. Bats were found to be at very low risk of contracting the novel coronavirus via their ACE2 receptor, which is consistent with actual experimental data.Whether bats directly transmitted the novel coronavirus directly to humans, or whether it went through an intermediate host, is not yet known, but the study supports the idea that one or more intermediate hosts was involved. The data allow researchers to zero in on which species might have served as an intermediate host in the wild, assisting efforts to control a future outbreak of SARS-CoV-2 infection in human and animal populations.Additional authors on the study include: Marco Corbo, UC Davis Genome Center; Graham M. Hughes and Emma C. Teeling, University College Dublin, Ireland; Kathleen C. Keough and Katherine S. Pollard, UC San Francisco; Corrie A. Painter, Nicole S. Persky, Diane P. Genereux, Ross Swofford, Kerstin Lindblad-Toh and Elinor K. Karlsson, Broad Institute of MIT and Harvard, Cambridge, Massachussetts; Michael Hiller, Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany; Andreas R. Pfenning, Carnegie Mellon University, Pittsburgh; Huabin Zhao, Wuhan University, Wuhan, China; Oliver A. Ryder, San Diego Zoo Institute for Conservation Research, Escondido, and UC San Diego; Martin T. Nweeia, Harvard School of Dental Medicine, Boston, and Smithsonian Institution, Washington D.C.The research in this study was coordinated as part of the Genome 10K Organization, which includes the Bat1K, Zoonomia, the Vertebrate Genomes Project and the Earth BioGenome Project. Genomic information for the study was also provided the National Center for Biotechnology Information's GenBank, the San Diego Zoo's Frozen Zoo and the Smithsonian's Global Genome Initiative. This work was supported by the Robert and Rosabel Osborne Endowment.
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Animals
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August 21, 2020
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https://www.sciencedaily.com/releases/2020/08/200821120756.htm
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Cliff collapse reveals 313-million-year-old fossil footprints in Grand Canyon National Park
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Paleontological research has confirmed a series of recently discovered fossils tracks are the oldest recorded tracks of their kind to date within Grand Canyon National Park. In 2016, Norwegian geology professor, Allan Krill, was hiking with his students when he made a surprising discovery. Lying next to the trail, in plain view of the many hikers, was a boulder containing conspicuous fossil footprints. Krill was intrigued, and he sent a photo to his colleague, Stephen Rowland, a paleontologist at the University of Nevada Las Vegas.
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The trailside tracks have turned out to be even more significant than Krill first imagined. "These are by far the oldest vertebrate tracks in Grand Canyon, which is known for its abundant fossil tracks" says Rowland. "More significantly," he added, "they are among the oldest tracks on Earth of shelled-egg-laying animals, such as reptiles, and the earliest evidence of vertebrate animals walking in sand dunes."The track-bearing boulder fell from a nearby cliff-exposure of the Manakacha Formation. The presence of a detailed geologic map of the strata along the Bright Angel Trail, together with previous studies of the age of the Manakacha Formation, allowed the researchers to pin down the age of the tracks quite precisely to 313 +/- 0. 5 million years.The newly discovered tracks record the passage of two separate animals on the slope of a sand dune. Of interest to the research team is the distinct arrangement of footprints. The researchers' reconstruction of this animal's footfall sequence reveals a distinctive gait called a lateral-sequence walk, in which the legs on one side of the animal move in succession, the rear leg followed by the foreleg, alternating with the movement of the two legs on the opposite side. "Living species of tetrapods―dogs and cats, for example―routinely use a lateral-sequence gait when they walk slowly," says Rowland. "The Bright Angel Trail tracks document the use of this gait very early in the history of vertebrate animals. We previously had no information about that." Also revealed by the trackways is the earliest-known utilization of sand dunes by vertebrate animals.
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Animals
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August 20, 2020
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https://www.sciencedaily.com/releases/2020/08/200820143836.htm
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Animal mummies unwrapped with hi-res 3D X-rays
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Three mummified animals from ancient Egypt have been digitally unwrapped and dissected by researchers, using high-resolution 3D scans that give unprecedented detail about the animals' lives -- and deaths -- over 2000 years ago.
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The three animals -- a snake, a bird and a cat -- are from the collection held by the Egypt Centre at Swansea University. Previous investigations had identified which animals they were, but very little else was known about what lay inside the mummies.Now, thanks to X-ray micro CT scanning, which generates 3D images with a resolution 100 times greater than a medical CT scan, the animals' remains can be analysed in extraordinary detail, right down to their smallest bones and teeth.The team, led by Professor Richard Johnston of Swansea University, included experts from the Egypt Centre and from Cardiff and Leicester universities.The ancient Egyptians mummified animals as well as humans, including cats, ibis, hawks, snakes, crocodiles and dogs. Sometimes they were buried with their owner or as a food supply for the afterlife.But the most common animal mummies were votive offerings, bought by visitors to temples to offer to the gods, to act as a means of communication with them. Animals were bred or captured by keepers and then killed and embalmed by temple priests. It is believed that as many as 70 million animal mummies were created in this way.Although other methods of scanning ancient artefacts without damaging them are available, they have limitations. Standard X-rays only give 2-dimensional images. Medical CT scans give 3D images, but the resolution is low.Micro CT, in contrast, gives researchers high resolution 3D images. Used extensively within materials science to image internal structures on the micro-scale, the method involves building a 3D volume (or 'tomogram') from many individual projections or radiographs. The 3D shape can then be 3D printed or placed into virtual reality, allowing further analysis.The team, using micro CT equipment at the Advanced Imaging of Materials (AIM) facility, Swansea University College of Engineering, found:Professor Richard Johnston of Swansea University College of Engineering, who led the research, said:"Using micro CT we can effectively carry out a post-mortem on these animals, more than 2000 years after they died in ancient Egypt.With a resolution up to 100 times higher than a medical CT scan, we were able to piece together new evidence of how they lived and died, revealing the conditions they were kept in, and possible causes of death.These are the very latest scientific imaging techniques. Our work shows how the hi-tech tools of today can shed new light on the distant past."Dr Carolyn Graves-Brown from the Egypt Centre at Swansea University said:"This collaboration between engineers, archaeologists, biologists, and Egyptologists shows the value of researchers from different subjects working together.Our findings have uncovered new insights into animal mummification, religion and human-animal relationships in ancient Egypt."The research was published in The authors respectfully acknowledge the people of ancient Egypt who created these artefacts.
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Animals
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August 20, 2020
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https://www.sciencedaily.com/releases/2020/08/200820143232.htm
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Dinosaurs' unique bone structure key to carrying weight
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Weighing up to 8,000 pounds, hadrosaurs, or duck-billed dinosaurs were among the largest dinosaurs to roam the Earth. How did the skeletons of these four-legged, plant-eating dinosaurs with very long necks support such a massive load?
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New research recently published in "The structure of the trabecular, or spongy bone that forms in the interior of bones we studied is unique within dinosaurs," said Tony Fiorillo, SMU paleontologist and one of the study authors. The trabecular bone tissue surrounds the tiny spaces or holes in the interior part of the bone, Fiorillo says, such as what you might see in a ham or steak bone."Unlike in mammals and birds, the trabecular bone does not increase in thickness as the body size of dinosaurs increase," he says. "Instead it increases in density of the occurrence of spongy bone. Without this weight-saving adaptation, the skeletal structure needed to support the hadrosaurs would be so heavy, the dinosaurs would have had great difficulty moving."The interdisciplinary team of researchers used engineering failure theories and allometry scaling, which describes how the characteristics of a living creature change with size, to analyze CT scans of the distal femur and proximal tibia of dinosaur fossils.The team, funded by the National Science Foundation Office of Polar Programs and the National Geographic Society, is the first to use these tools to better understand the bone structure of extinct species and the first to assess the relationship between bone architecture and movement in dinosaurs. They compared their findings to scans of living animals, such as Asian elephants and extinct mammals such as mammoths."Understanding the mechanics of the trabecular architecture of dinosaurs may help us better understand the design of other lightweight and dense structures," said Trevor Aguirre, lead author of the paper and a recent mechanical engineering Ph.D. graduate of Colorado State University.The idea for the study began ten years ago, when Seth Donahue, now a University of Massachusetts biomedical engineer and expert on animal bone structure, was invited to attend an Alaskan academic conference hosted by Fiorillo and other colleagues interested in understanding dinosaurian life in the ancient Arctic. That's where Fiorillo first learned of Donahue's use of CT scans and engineering theories to analyze the bone structure of modern animals."In science we rarely have lightning bolt or 'aha' moments," Fiorillo says. "Instead we have, 'huh?' moments that often are not close to what we envisioned, but instead create questions of their own."Applying engineering theories to analyze dinosaur fossils and the subsequent new understanding of dinosaurs' unique adaptation to their huge size grew from the 'huh?' moment at that conference.
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Animals
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August 20, 2020
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https://www.sciencedaily.com/releases/2020/08/200820112848.htm
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Ichthyosaur's last meal is evidence of Triassic megapredation
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Some 240 million years ago, a dolphin-like ichthyosaur ripped to pieces and swallowed another marine reptile only a little smaller than itself. Then it almost immediately died and was fossilized, preserving the first evidence of megapredation, or a large animal preying on another large animal. The fossil, discovered in 2010 in southwestern China, is described in a paper published Aug. 20 in the journal
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The ichthyosaurs were a group of marine reptiles that appeared in the oceans after the Permian mass extinction, about 250 million years ago. They had fish-like bodies similar to modern tuna, but breathed air like dolphins and whales. Like modern orca or great white sharks, they may have been apex predators of their ecosystems, but until recently there has been little direct evidence of this.When a specimen of the ichthyosaur Guizhouichthyosaurus was discovered in Guizhou province, China in 2010, researchers noticed a large bulge of other bones within the animal's abdomen. On examination, they identified the smaller bones as belonging to another marine reptile, Xinpusaurus xingyiensis, which belonged to a group called thalattosaurs. Xinpusaurus was more lizard-like in appearance than an ichthyosaur, with four paddling limbs."We have never found articulated remains of a large reptile in the stomach of gigantic predators from the age of dinosaurs, such as marine reptiles and dinosaurs," said Ryosuke Motani, professor of earth and planetary sciences at the University of California, Davis, and coauthor on the paper. "We always guessed from tooth shape and jaw design that these predators must have fed on large prey but now we have direct evidence that they did."The Guizhouichthyosaurus was almost five meters (15 feet) long, while the researchers calculate its prey was about four meters (12 feet) long, although thalattosaurs had skinnier bodies than ichythyosaurs. The predator's last meal appears to be the middle section of the thalattosaur, from its front to back limbs. Interestingly, a fossil of what appears to be the tail section of the animal was found nearby.Predators that feed on large animals are often assumed to have large teeth adapted for slicing up prey. Guizhouichthyosaurus had relatively small, peg-like teeth, which were thought to be adapted for grasping soft prey such as the squid-like animals abundant in the oceans at the time. However, it's clear that you don't need slicing teeth to be a megapredator, Motani said. Guizhouichthyosaurus probably used its teeth to grip the prey, perhaps breaking the spine with the force of its bite, then ripped or tore the prey apart. Modern apex predators such as orca, leopard seals and crocodiles use a similar strategy.
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August 20, 2020
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https://www.sciencedaily.com/releases/2020/08/200820102432.htm
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Australia's wish list of exotic pets
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Unsustainable trade of species is a major pathway for the introduction of invasive alien species at distant localities and at higher frequencies. It is also a major driver of over-exploitation of wild native populations. In a new study, published in the peer-reviewed open-access scholarly journal
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Over the last two decades, Australia has been experiencing an increased amount of non-native incursions from species prominent in the international pet trade, such as rose-ringed parakeets, corn snakes and red-eared sliders. On many occasions, these animals are smuggled into the country only to escape or be released in the wild.In general, the Australian regulations on international pet trade are highly stringent, in order to minimise biosecurity and conservation risks. Some highly-desirable species represent an ongoing conservation threat and biosecurity risk via the pet-release invasion pathway. However, lack of consistent surveillance of alien pets held, legally or otherwise, in Australia remains the main challenge. While there are species which are not allowed to be imported, they are legal for domestic trade within the country. Pet keepers have the capacity to legally or illegally acquire desired pets if they are not accessible through importation, and the number of such traders is unquantified.Since keeping most of the alien pets in Australia is either illegal or not properly regulated, it is really difficult to quantify and assess the public demand for alien wildlife."We obtained records of anonymous public enquiries to the Australian Commonwealth Department of Agriculture, Water and the Environment relating to the legality of importation of various alien taxa. We aimed to investigate whether species desired in Australia were biased towards being threatened by extinction, as indicated by broader research on pet demand or towards being invasive species elsewhere, which would indicate trade-related biosecurity risks," shares the lead author Mr. Adam Toomes from the University of Adelaide.According to the research team's analysis, pets desired by Australians are significantly biased towards threatened species, invasive species and species prominent in the U.S. pet trade."This novel finding is of great concern for biosecurity agencies because it suggests that a filtering process is occurring where illegally smuggled animals may already be "pre-selected" to have the characteristics that are correlated with invasive species," warns Mr. Adam Toomes.However, the bias towards species already traded within the U.S. suggests that there is potential to use this as a means of predicting future Australian desire, as well as the acquisition of pets driven by desire. Future research from the Invasion Science & Wildlife Ecology Group at The University of Adelaide will investigate whether Australian seizures of illegal pets can be predicted using U.S. trade data.
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August 20, 2020
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https://www.sciencedaily.com/releases/2020/08/200820102409.htm
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An active lifestyle reduces fearfulness in dogs - differences between breeds are great
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Noise sensitivity, fear of novel situations and, for example, fear of slippery surfaces and heights are common behavioural problems among dogs. According to a behavioural survey of nearly 14,000 dogs conducted at the University of Helsinki, these non-social fears are associated with factors related to the dogs' living environment, lifestyle and breed.
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Dogs that were engaged in activities the most and were actively trained were found to be the least fearful."Physical exercise has been shown to have a positive effect on the mood in both dogs and humans. As social animals, dogs enjoy doing things with their owners. At the same time, people do not necessarily wish to subject fearful dogs to training situations that are stressful for them. This can also make owners less inclined to train with their dog," says doctoral student Emma Hakanen from the Faculty of Medicine, University of Helsinki.The survey indicates that insufficient socialisation of puppies to various situations and new environments in particular has a strong link with fearfulness related to novel situations, loud noises as well as different walking surfaces, such as slippery surfaces, transparent stairs or metal grilles. On the other hand, the company of other dogs reduced the occurrence of non-social fear.Fear of fireworks and surfaces was more prevalent among the dogs of first-time dog owners, while differences were also seen between rural and urban dogs."Our prior research on the environmental effects of social fear observed the same phenomena where urban dogs were more fearful than their rural counterparts. Indeed, it is interesting that human mental health problems too occur more frequently in the city than in rural areas. The ways in which our environment shapes us and our best friend is definitely an interesting topic for further research," says Professor Hannes Lohi from the Faculty of Veterinary Medicine and Faculty of Medicine, University of Helsinki.Furthermore, as suggested by prior research, the study demonstrated that non-social fearfulness also is more common in sterilised females and small dogs. Being fearful of slippery or otherwise unfamiliar surfaces was also associated with a generally fearful disposition in dogs.Significant differences between breeds were identified in the study, with Cairn Terriers among the most fearful breeds and Chinese Crested Dogs among the least fearful.However, variance was seen between different non-social fears in the fearfulness of individual breeds. For instance, Welsh Corgi Pembrokes expressed a lot of noise sensitivity but little fearfulness of surfaces. At the same time, the latter was common among Lapponian Herders, Miniature Schnauzers, Chihuahuas and Labrador Retrievers, while noise sensitivity was less so."The breed-specific differences support the idea that fearfulness is inherited. In other words, breeding choices matter, even without knowing the exact mechanisms of inheritance. However, this study offers dog owners tools and support for previous notions related to improving the wellbeing of their dogs. Diverse socialisation in puppyhood and an active lifestyle can significantly reduce social and non-social fearfulness," Lohi sums up.The study is part of Professor Lohi's wider Academy of Finland project, which investigates the epidemiology of canine behaviour, as well as related environmental and genetic factors and metabolic changes.
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August 19, 2020
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https://www.sciencedaily.com/releases/2020/08/200819120657.htm
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Termite-fishing chimpanzees provide clues to the evolution of technology
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Researchers, who remotely videotaped a generation of wild chimpanzees learning to use tools, gain insights into how technology came to define human culture.
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Using the now-ubiquitous humanmade technology of motion-activated cameras, researchers who remotely watched 25 immature chimpanzees grow up have documented how humankind's closest relatives living in the Congo Basin acquire their unique tool skills for harvesting termites, a favorite nutrient-rich element of the chimpanzee diet.Unlike chimpanzees in East and West Africa, who use a single tool to extract termites, chimpanzees in Central Africa's Congo Basin use tool sets -- puncturing sticks or perforating twigs plus fishing probes -- to harvest the insects from underground nests or towering earthen mounds scattered across lowland forests. Arguably, chimpanzees living in this region have the most sophisticated arsenal of tool-using skills documented in the animal kingdom. Not only do they use specialized tool sets to harvest termites, ants, and honey, but they customize the implements with different modifications to improve their efficiency.Trying to untangle how chimpanzees in the Congo Basin acquire these complex tool tasks, University of Miami biological anthropologist Stephanie Musgrave screened thousands of hours of video that recorded visits to termite nests, including those by forest elephants, leopards, and gorillas, in the Republic of Congo's Goualougo Triangle. Her reward was identifying more than 660 hours of periodic visits by 25 young chimpanzees belonging to a notoriously elusive subspecies of chimpanzee (Pan troglodytes troglodytes). Recorded over 15 years, this footage captured the development of their tool-using skills from birth until maturity.Now, in the first study assessing when Central African chimpanzees learn to use and make their unique termite-extracting tool sets, Musgrave and fellow researchers with the Goualougo Triangle Ape Project provide novel insights into how chimpanzee cultures persist over generations -- and perhaps how technology came to be a defining aspect of human evolution."Chimpanzees have the most complex tool behaviors of any animals outside of humans, so studying how their youngsters become proficient at these tasks can help us better understand how early humans might have acquired complex technological skills," said Musgrave, an assistant professor in the Department of Anthropology and lead author of the study published in the "Examining the development of these perishable tool kits is of particular interest because our ancestors likely also used perishable tools -- made of plants rather than stone -- but these tools are not preserved in the archeological record," she added.For their study, Musgrave and her co-authors -- Elizabeth Lonsdorf, David Morgan, and Crickette Sanz -- conducted the first, direct comparison of tool skill acquisition between two populations of chimpanzees, those at Goualougo and those more than 1,300 miles to the east, in Gombe, Tanzania.Lonsdorf, a professor of psychology at Franklin & Marshall College, studies chimpanzees at Gombe, the oldest field study of wild chimpanzees established by renowned primatologist Jane Goodall 60 years ago. Morgan, of Chicago's Lincoln Park Zoo, and Sanz, of Washington University in St. Louis, co-founded the Goualougo Triangle Ape Project -- the longest-running behavioral study of wild Central African chimpanzees. And, in partnership with the Wildlife Conservation Society, they have studied this population of chimpanzees for more than 20 years. They also pioneered the use of remote video technology to study wild chimpanzee behavior.For their current study, the research team adapted the methods developed at Gombe for studying the acquisition of tool skills. And, they found notable differences in the timing and sequence in which the chimpanzees in these two populations acquired their termite-gathering skills -- differences that could relate to the challenges of using and making multiple tools at Goualougo.While infants at both Goualougo and Gombe begin trying to use tools within their first two years, the Gombe youngsters learn to make their tools before or at the same time they become proficient at using them. In contrast, the Goualougo youngsters learn to termite fish before acquiring their tool-making skills. In early life, they typically use tools that have been discarded or transferred to them by other, older chimpanzees.Unlike the Gombe chimpanzees, who use varied materials, the Goualougo chimpanzees also carefully select the materials for their tools, almost always from just a few species of plants. And they modify them to improve their efficiency."They have a mental template of the right tool for the job, and there's no mistaking the different tool types," Musgrave said. "Puncturing tools are made from a species of tree that's very durable and resistant, while fishing probes are made from smooth, pliable stems of vegetation. In contrast to Gombe, the chimpanzees at Goualougo fray these probes with their teeth to manufacture a paint-brush-like tip, which makes the tool 10 times more efficient at capturing termites."After learning to make their own tools, Musgrave discovered, the Goualougo chimpanzees begin to employ them sequentially -- using a perforating twig plus a fishing probe to harvest the termites that inhabit the above-ground nests and a puncturing stick plus a fishing probe to extract them from the much-harder-to-pierce underground nests. The latter task is so arduous that the researchers predicted it would be the last mastered and just by a few chimpanzees. They were right."I've observed chimpanzees make hundreds of attempts to puncture into a subterranean termite nest," Musgrave said. "Not only does the skill require immense strength but also technical competencies that may continue to develop in adolescence."The findings underscore how the developmental trajectory of life skills can vary considerably depending on the task and across chimpanzee populations, which have unique local cultures. In the study, the researchers note that the variation in tool traditions between sites could be linked to differences in the role of social input from other chimpanzees."In previous research, we documented that mother chimpanzees at Goualougo play a more active and helpful role when compared to mothers at Gombe," Musgrave said. "At Goualougo, mothers are more likely to transfer tools to their offspring. This enhanced assistance could be instrumental in the acquisition of skills over the longer time period."Figuring out how tool traditions are passed on and how this differs within and between species, Musgrave said, could help humans understand the emergence of cumulative culture during our own evolution."One of the key features of human culture is its remarkable complexity," she said. "It's what we call cumulative. Meaning that ideas and innovations accumulate over time, such that new generations inherit and learn to use technologies that are far more complex than any one individual could invent. Comparative studies give us insights into how technology came to be a defining aspect of human evolution."But, as Musgrave cautioned, the continuation and expansion of such research depends on the long-term preservation of wild chimpanzees and their cultures -- which are increasingly endangered by human activities.
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August 19, 2020
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https://www.sciencedaily.com/releases/2020/08/200819084957.htm
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Illegal trade with terrestrial vertebrates in markets and households of Laos
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It's not a surprise to anyone that numerous vertebrate species are being sold at different wildlife markets, but at the moment there is still no comprehensive understanding of how much people are involved in those actions in Laos (Lao PDR), nor what the impact on local wildlife populations really is.
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The majority of Laotians live in rural areas and their income largely depends on wildlife. Since wildlife products are used as one of the major food sources, numerous species of terrestrial vertebrates are currently being offered at local markets.Across the tropical regions, mammals and birds have been vanishing, with recent models estimating up to 83% decline by 2050. Furthermore, wild-caught reptiles have been reported from Southeast Asian wildlife markets for over 20 years, with Laos occupying the position of a very popular source.Due to the large number of native endemic species, Lao PDR should assume the responsibility to introduce conservation measures to keep control over the predicted population declines. At the moment, the regulations on wildlife use and trade in Laos are mostly based on the Lao Wildlife and Aquatic Law, which, however, largely disregards international statuses of the species and other biological factors.Stricter and reinforced legislation is needed in the fields related to wildlife trade and consumption, since such practices are not only causing biodiversity loss, but also suggested to pose a great threat of wildlife-associated emergence of zoonotic parasites and pathogens to humans. As an immediate example, the outbreak of the Coronavirus (COVID-19) is primarily considered to be a consequence of human consumption of wild animals.An international group of students and scientists, led by Professor Dr. Thomas Ziegler at the University of Cologne and the Cologne Zoo (Germany), has conducted a number of extensive surveys on wildlife markets (66 observational surveys at 15 trade hubs) and households (63 households at 14 sites) in the Khammouane Province of Laos. The key question of the survey was: "Which species are traded and to what extent?" The results of the study are published in the open-access journal The surveys showed overlaps between the most traded species at wildlife markets and those of highest conservation importance.As for the households, approximately 90% of the surveyed respondents confirmed the use of wildlife. For the majority of the population, wildlife harvesting was found to be important for their livelihood and trapping activities were mostly aimed at self-consumption / subsistence. The reason for this could be explained by the prices of domesticated meat, which can be three times as higher as those of wildlife products.The demand for the species on the wildlife market remained the same over time, according to the opinions of 84,1% of respondents, while the availability of wild meats was reported to have decreased, due to increasing price."We recommend local authorities to assess the markets within the province capital Thakhek in particular, as they showed the highest quantity of wild meats. The markets at Namdik and Ban Kok turned out to be very active trade hubs for wildlife as well, regardless of the vertebrate group. The loss of certain species may cause a cascade of unforeseeable effects in the ecosystems. Therefore, the biodiversity of tropical Southeast Asian countries like Lao PDR must be protected.," shares Dr. Thomas Ziegler.To help the local population to avoid the crisis related to the change of activity and growing unemployment, scientists propose to introduce new activities in the region."Eco-tourism presents a great opportunity to combine conservation efforts and an alternative source of income. Former hunters with excellent knowledge of the forest and wildlife habitats can serve as professional wildlife tour guides or their involvement in the Village Forest Protection Group could help to protect natural resources in Laos," suggests Dr. Thomas Ziegler.
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August 18, 2020
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https://www.sciencedaily.com/releases/2020/08/200818142147.htm
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Why doesn't Ebola cause disease in bats, as it does in people?
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A new study by researchers from The University of Texas Medical Branch at Galveston uncovered new information on why the Ebola virus can live within bats without causing them harm, while the same virus wreaks deadly havoc to people. This study is now available in
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The Ebola virus causes a devastating, often fatal, infectious disease in people. Within the past decade, Ebola has caused two large and difficult to control outbreaks, one of which recently ended in the Democratic Republic of the Congo.When a virus brings serious disease to people, it means that humans are not good hosts for the virus. Viruses depend on a living host for their survival and have natural reservoirs -- a hosting animal species in which a virus naturally lives and reproduces without causing disease. Bats are likely a natural reservoir for the Ebola virus, but little is known about how the virus evolves in bats.Like most other RNA viruses, Ebola's molecules are structured in a way that makes them more prone to genomic errors and mutations than other types of viruses. Because of this, Ebola and similar viruses have a remarkable ability to adapt to and replicate in new environments.In the study, the research team, led by Alex Bukreyev, a UTMB virologist in the departments of pathology and microbiology and immunology, working with the team of Raul Andino, University of California, San Francisco, investigated how the Ebola virus adapts to both bat and human cells. They assessed changes in mutation rates and the structure of Ebola virus populations repeatedly in both bat and human cell lines using an ultra-deep genetic sequencing."We identified a number of meaningful differences in how the Ebola virus evolves when placed in a human cell line relative to a bat cell line," Bukreyev said. "For instance, the RNA editing enzyme called ADAR within bat cells play a greater role in the replication and evolution of the Ebola virus than do such enzymes in human cells. We found that the envelope protein of Ebola virus undergoes a drastic increase in certain mutations within bat cells, but this was not found in human cells. This study identifies a novel mechanism by which Ebola virus is likely to evolve in bats."The study suggests that the Ebola virus and bats can live together harmoniously because of the bat cell's ability to induce changes in the virus that make it less capable of harm. Bukreyev said that the study's findings validate the ultra-deep genetic sequencing used in this study as a predictive tool that can identify viral mutations associated with more adaptive evolution. This technology can be very useful in studying, and perhaps shaping, the evolution of emerging viruses, like SARS-CoV-2, the virus responsible for COVID-19.
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August 18, 2020
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https://www.sciencedaily.com/releases/2020/08/200818142130.htm
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Down syndrome mice open door to better understanding of the disorder
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Scientists across the globe often use mouse models in the study of human conditions to advance the pursuit of medicines and treatments. Now, Johns Hopkins Medicine researchers and their collaborators have created and characterized a new mouse replica of Down syndrome, long considered one of the most challenging disorders to simulate in laboratory animals.
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A report of their research appeared June 29, 2020, in the journal The new model may help researchers better understand how people with Down syndrome learn and develop, and eventually, lead to new therapies for potentially deadly complications of the condition, such as heart disease and thyroid problems.Down syndrome, caused by trisomy 21, occurs when a person is born with an extra partial or entire copy of the 21st chromosome. Typically associated with distinct facial features and developmental delays, people with Down syndrome also experience difficulties with learning and memory, as well as higher rates of thyroid disease, blood and immune disorders and heart disease. Treating these conditions in people with Down syndrome is complicated by their genetics."There are more than 500 genes on chromosome 21 that can be overexpressed," says Roger Reeves, Ph.D., professor of physiology at the Johns Hopkins University School of Medicine. "So, in comparison to many other genetic conditions, Down syndrome is vastly more complex."Further complicating the development of successful treatments is the lack of an accurate animal model to study the biology of Down syndrome and test potential therapies for conditions associated with it.Reeves and his team endeavored to improve research efforts by creating a more precise replica of the condition in mice. They did this by inserting a human copy of chromosome 21 into mice using the rodent's own cellular structures that organize DNA. This enables the mouse cells to reliably copy and sort the extra human chromosome into new cells as they divide. It also lets the mice pass the additional genetic material on to their offspring.This means that these mice, named TcMAC21 by the researchers, can be used relatively easily and at low cost in long-term experiments.The resulting TcMAC21 mice have many characteristics indicative of Down syndrome in humans, including a distinct facial structure, a greater prevalence for congenital heart defects, a smaller-than-usual cerebellum and learning difficulties.The researchers caution that no single animal model can perfectly replicate a human condition. However, they believe that the TcMAC21 mouse model developed in this study is a good starting point to create new and better strategies for helping people with Down syndrome."Our goal is to improve the health of people with Down syndrome to give them the best chance at achieving their full potential," says Reeves.
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August 18, 2020
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https://www.sciencedaily.com/releases/2020/08/200818142123.htm
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Horse skeletons provide clues to preventing racehorse injuries
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In an anatomical comparison of the third metacarpal, or cannon bone, among Thoroughbred racehorses, American Quarter Horses and feral Assateague Island ponies, Johns Hopkins Medicine researchers have found that fostering adaptations in these bones through training might help horses better endure the extreme conditions of racing and prevent serious, often life-ending injuries on the track.
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Racehorses operate at a biomechanical extreme. The 1,000-pound or so animals can move up to 40 miles per hour on long, thin limbs genetically evolved to move them across long distances.When pushed to race at high speeds, a horse's legs can fracture beneath them in an event called a breakdown. Seventy percent of these injuries occur in the third metacarpal bone between the horse's knee and pastern (the area just above the top of the hoof). Because of the fragile nature of their limbs, breaks such as these can cause irreparable tissue damage, resulting most often in the animal having to be euthanized."With so many Thoroughbreds breaking their legs this way, we thought there must be a way to predict and prevent it," says Deanna Goldstein, a doctoral candidate in the Center for Functional Anatomy and Evolution at the Johns Hopkins University School of Medicine and lead author on the paper, posted online August 17, 2020, in the journal To understand why racehorses break down, Goldstein compared the sizes, densities and abilities to bend without breaking of the three types of canon bones studied to examine the effect on them from each breed's lifestyle and training.Thoroughbreds, for example, are trained to run long distances around turns for races like the Kentucky Derby. American Quarter Horses are trained to sprint short distances in mostly straight lines, and are named for their superior ability to run a quarter mile faster than any other breed. Assateague Island ponies are shorter, stockier animals that live wild, and therefore, offered an untrained population against which to compare Quarter Horses and Thoroughbreds."Comparisons between these breeds present an interesting opportunity to look at the relationship between the mechanical stresses on the bone and the bone's structural response in an animal that is pushed to its physiological limits," says Goldstein.In the study, bones were collected only from horses who died or were euthanized for reasons unrelated to a broken or injured third metacarpal bone.Although the size of the third metacarpal bone varied among the three horse breeds, Goldstein was surprised to find that the bone's strength and structure relative to body size were remarkably similar across the three types of horses."If Thoroughbreds are racing and training around turns, you would expect certain areas of their bones to be a lot stronger to reflect that," says Goldstein. "However, since the Thoroughbred third metacarpals are not more dense or stronger than the other two breeds, it indicates that the Thoroughbreds' bones are just not prepared for those forces."What should be seen, says Goldstein, is evidence of bone remodeling -- the process by which new bone growth helps the skeleton respond to mechanical stress. Similar to how weightlifting strengthens human bones, exposure to the stresses of racing around turns should create anatomical differences between Thoroughbred horses and other breeds. These adaptations would prepare their bones to resist fracturing.Goldstein suggests that adding training around tighter turns at higher speeds could give Thoroughbred horses' bones time to adapt to the extreme forces and be more resistant to breaks on the track.Thoroughbred horseracing has been mired in controversy as numerous accounts, such as one in a June 22, 2019, article in the New York Times, reveal a growing number of fatalities in the sport, with many attributable to leg fractures. While some of these cases have been linked to animals being given performance-enhancing drugs, Goldstein and her colleagues believe that scientifically backed interventions in how racehorses are managed and trained could better protect them from stress-related breakdowns on the track.
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August 18, 2020
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https://www.sciencedaily.com/releases/2020/08/200818114950.htm
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Free-roaming dogs prevent giant pandas from thriving in the wild
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Before China declared giant pandas a protected species in 1962 -- hunters in pursuit of the black and white bear used dogs to track them. Since then measures have been put in place to protect the vulnerable pandas, but more than half a century later, dogs are still jeopardizing their safety, according to a group of researchers that included Drexel's James Spotila, PhD.
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Spotila, the L.D. Betz Chair Professor in the Department of Biodiversity, Earth and Environmental Science in Drexel's College of Arts and Sciences, and the group began to investigate the problem after two captive-born pandas, which had been released into Liziping Nature Reserve, were attacked by dogs.The group found that dogs are still menacing giant pandas in part because nature reserves in China are often closely connected to human settlements where dogs roam free. Dogs can roam over 10 km in a night and some feral dogs have even set up permanent residence in the reserves.A GIS analysis of Liziping Nature Reserve revealed this to be the case, as much of that reserve was within the range of free roaming dogs from the nearby villages. The finding led researchers to expand their scope and suggest that reserves designated for the release of translocated pandas should receive priority consideration for dog-control efforts.Pandas are vulnerable species in part because they require a minimum habitat size of 114 square-kilometers to thrive. While most nature reserves designated for giant pandas are large enough to sustain their population, encroachment by free-roaming dogs could significantly limit the bears' territory.Because of this concern, the research team, working out of Chengdu Research Base, expanded its analysis to include all giant panda reserves in China, which revealed that across the entire range 40% of panda habitats are within range of roaming dogs. Therefore, the area safely available for giant pandas in nature reserves throughout China is only 60% of the official "protected" area."Dogs have to be removed from giant panda reserves if they are to survive in the wild," Spotila said. "Predation, harassment and disease transmission by dogs can have large-scale edge effects in both fragmented habitats and protected nature reserves."The team recently published its findings in Spotila believes that China has done a good job in its conservation efforts, but dog-control efforts need to be considered and implemented in order for giant pandas to thrive in the wild."Only by understanding and managing complex interactions between humans, domestic animals and wild animals can we sustain natural systems in a world increasingly dominated by humans," Spotila said.
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August 18, 2020
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https://www.sciencedaily.com/releases/2020/08/200818114948.htm
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How a single gene drives aggression in wild songbird
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A new study shows how differentiation of a single gene changes behavior in a wild songbird, determining whether the white-throated sparrow displays more, or less, aggression. The
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The researchers singled out an estrogen receptor from a complex of more than 1,000 genes known as a "supergene," or genetic material inherited together as a block. The work provides a rare look at how genomic divergence can lead to behavioral divergence in a vertebrate."Evolution has tinkered with the DNA sequence of a gene of this songbird, and we demonstrated that those little changes affect both the expression of the gene and the bird's behavior," says Emory graduate student Jennifer Merritt, first author of the paper.Merritt is a PhD candidate in the lab of Donna Maney, senior author of the paper and an Emory professor of psychology."White-throated sparrows are common backyard birds found through most of North America," Merritt says. "What's remarkable about them is that they occur in two different morphs that have not only different plumage, but also different strategies for maximizing reproductive output. Both types of differences are caused by genetic differentiation of only one region of a single chromosome, and we know exactly where it is."At some point during the evolution of a species, a chromosome can break and flip. This process, called an inversion, isolates the genes that are trapped inside, producing a supergene. In some cases, supergenes have led to distinct morphs within a single species -- individuals with the supergene and those without it.In the case of the white-throated sparrows, the white-striped morph sports bright yellow, black and white stripes on its crown while the tan-striped morph has more muted, tan and grayish stripes. The white-striped birds, which all possess at least one copy of the rearranged chromosome, tend to be more aggressive and less parental than the tan-striped birds, which do not have the rearranged chromosome."Scientists have hypothesized for 100 years that inversions are important for the evolution of some of the complex behaviors that we see in nature," Maney says. "But inversions are challenging to understand because, when they turn into supergenes, all of the genes are inherited together. We already knew a lot about the natural history of the white-throated sparrow, as well as the biological mechanisms underlying its aggression. Using that knowledge, we were able to finally show the evolutionary role of a supergene at the molecular level."The current paper builds on previous work by the Maney lab, a leader in connecting gene sequence with behavior in free-living animals. In 2014, the lab identified a hormone receptor -- estrogen receptor alpha (ER-alpha) -- that appeared connected to the differences in the sparrows' aggression and parenting behaviors in the wild. The white-striped birds express this receptor at much higher levels than the tan-striped birds, and the more the expression, the more aggressive the bird."For this paper, we wanted to follow the genetic variation of ER-alpha all the way up to where it's expressed in the brain, and then to behavior, to see if we could trace the behavioral variation to variation in this one gene," Merritt says.The birds sing to establish a territory. The rate at which they sing gives a measure of their level of aggression, along with the frequency at which they charge, or "attack," animals encroaching on what they consider their territory.In field studies of white-throated sparrows in their natural habitat, the researchers showed that the more a bird expresses the supergene version of the estrogen receptor, the more vigorously it defends its territory.The researchers then moved beyond the correlational work by taking an experimental approach. White-throated sparrows in the lab were given a substance to block expression of the ER-alpha gene and their aggression levels were measured. The results showed that when expression of that one gene was blocked, the aggression of the white-striped birds went down so they behaved like the tan-striped ones."We believe this is the first demonstration of how a single gene within a supergene drives changes in a social behavior in a wild vertebrate," Merritt says. She gives an analogy for the challenge involved: "Imagine each of the genes within a supergene as tributaries converging into a river, the behavior. And then taking a sample of water from the river and determining which tributary the sample came from."The Maney lab is continuing to investigate a suite of other neuroendocrine genes captured by the chromosome rearrangement in the white-throated sparrow that are thought to be important players in the regulation of social behavior.Co-authors of the PNAS paper include Eric Ortlund, a biochemist and an expert in the ER-alpha gene at the Emory School of Medicine; Kathleen Grogan and Wendy Zinzow-Kramer, former post-doctoral fellows in the Maney lab; and Dan Sun and Soojin Yi, from Georgia Tech. The work was funded by grants from the National Institutes of Health and the National Science Foundation.
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August 18, 2020
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https://www.sciencedaily.com/releases/2020/08/200818103835.htm
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Native Hawaiian tiger cowries eat alien invasive species
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Researchers at the University of Hawai'i (UH) at Manoa's Hawaii Institute of Marine Biology (HIMB) have just discovered that the Hawaiian tiger cowrie (Leho-kiko in Hawaiian) is a voracious predator of alien sponges such as the Orange Keyhole sponge, which can overgrow native corals and has become a concern as it spread across reefs within K?ne?ohe Bay. In the study published recently, researchers found that each cowrie eats more than half their body weight in sponges each week.
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"We found that cowries ate most species of alien sponges that we offered them, and that a single snail can consume an entire sponge the size of your fist in roughly a week," said Jan Vicente, lead author of the study and postdoctoral researcher at HIMB in the UH M?noa School of Ocean and Earth Science and Technology (SOEST).Alien invasive species, such as killer algae in the Mediterranean or lionfish in the Caribbean, can devastate native ecosystems. Hawai?i ranks among the highest in the world for both the number of marine alien invasive species and the success of those invaders in taking over space from native species. Prevention, early detection, and rapid removal are the best tools to prevent impacts from alien species, because once invaders become established, efforts to eradicate them are expensive and often unsuccessful.One relatively cheap option for management of alien species is known as biocontrol, in which a natural predator of the alien species is also introduced to control the invader. Hawai?i is also home to some spectacular failures of past biocontrol efforts, such as the mongoose and wolf snail that created new problems rather than solving existing ones. However, not all biocontrol efforts need to use one alien species to control another, because in some cases a native species can serve that critical role to control an alien invader.Cowries have been overharvested throughout the Pacific and have experienced a precipitous decline in most populated locations. The Hawaiian tiger cowrie is more valuable than most, because it is not found anywhere else and reaches a much larger size. Tiger cowries, like most cowrie shells, have been in high demand for over 1000 years in Indo-Pacific trade, but harvest of the Hawaiian cowrie is unreported and unregulated by the state of Hawai'i."Our study shows that cowries may be able to control alien sponges if they were common enough, but we hear from the Native Hawaiian community that they are far less common today than in the past. We need to protect these culturally and ecologically important animals from overharvest. This study shows that Hawaiian tiger cowries could help control invasive species, so maybe we should stop people from killing them to sell as ornaments in the shell trade." said Vicente.Co-author and HIMB professor Rob Toonen was quick to add, "If these snails can do the work of controlling alien invasive species for us, it will save the state both time and money to keep them in the ocean rather than on display for someone's shelf."
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August 18, 2020
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https://www.sciencedaily.com/releases/2020/08/200818094017.htm
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Swans reserve aggression for each other
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Swans display more aggression to fellow swans than other birds, new research shows.
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The study examined three swan species -- mute, whooper and Bewick's -- and found all were most frequently aggressive to their own kind.The findings suggest that similar individuals are the greatest competition for food and other resources such as shelter, which can lead to conflict.The research, by the Wildfowl and Wetlands Trust (WWT) and the University of Exeter, was undertaken to better understand how swan behaviour affects other waterbirds over winter.Dr Kevin Wood, Principal Research Officer at WWT, said: "We know that swans have a reputation for aggressiveness but some of us suspected that in reality a lot of the aggression was directed towards other swans rather than smaller birds such as ducks or geese."To test that idea, we recruited some great students who used the webcams at Slimbridge and Caerlaverock to collect behavioural data on aggressive interactions between the various waterbirds at those sites over the past two winters."Our suspicions were right."In fact, almost all of the waterbird species in our study were most aggressive to their own species, which makes ecological sense as the individuals that are most similar to you are your greatest competition for food and other resources."It's valuable to finally have the data to show that, and it's another rung on the ladder of better-informed judgement on swans."The study was carried out by monitoring live-stream webcams on reserves at WWT Slimbridge Wetland Centre in Gloucestershire and WWT Caerlaverock Wetland Centre in Dumfries over the past two years.It's one of the first studies that has relied completely on remotely collected data -- and could be one of the solutions to continuing research with restrictions in place during the Covid-19 pandemic.Dr Paul Rose, of Exeter's Centre for Research in Animal Behaviour, added: "This is a great example of how undergraduate projects can really help wild conservation action by allowing students to practice key research techniques but at the same time collecting data that is valuable to field scientists."We'd been thinking of using the WWT webcams for a while, to learn more about the swans' behaviour without disturbing them, and this project on aggression and species differences seemed to beneficial to the needs of WWT's conservation work and to the students fulfilling the requirements of their degrees."Across whooper, Bewick's and mute swans, infighting between the same species accounted for up to 80% of negative interactions.Bewick's swans in particular were more likely to behave aggressively with one another, which could reflect their extreme lifestyles which involve a 7,000km migration across a continent twice a year.The number of wintering Bewick's swans in the UK declined by more than 50% between 1995 and 2015, with numbers continuing to fall.Conservationists have theorised that this may be due to competing with mute and whoopers swans at their winter sites in Europe and at summer sites in Arctic Russia.However, these findings show this is unlikely.The study has also helped demonstrate how remotely-collected data can inform scientific research, without causing as much disturbance to birds and reducing carbon footprint in terms of travel.It is likely to become an increasingly useful tool as conservationists try to carry out research while potential for field-work is limited.The next step is to study other waterbirds to see how their behaviour alters depending on the presence and number of swans.
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Animals
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August 17, 2020
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https://www.sciencedaily.com/releases/2020/08/200817144115.htm
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Where lions operate, grazers congregate ... provided food is great
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Meals are typically family affairs for zebras, gazelles, cape buffalo and other grazing species in the African Serengeti, but in one of the first studies of its kind, ecologists have found grazing species can be more willing to share meals in areas frequented by lions.
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The study, which is available online this week in the journal "The mixed-species groups occur near places where lions like to hunt, which suggests the grazers are trying to reduce their chances of being killed by predators," said Rice lead-author Lydia Beaudrot.Mixed-species groups of grazers were found in 1.9% of the camera-trap photos, which were collected between 2010-2015 in Tanzania's Serengeti National Park and processed by volunteers for the citizen science website snapshotserengeti.org. Camera-trap findings were combined with information from long-term GPS collar monitoring by the Serengeti Lion Project and satellite imagery that showed both the location of hunting areas favored by lions and where and when food was plentiful or scarce for grazers."Mixed-species groups were most likely in 'risky' places, like woodland habitats and near rocky outcroppings that lions use as viewsheds," said Beaudrot, an assistant professor of biosciences.But the threat from lions apparently isn't the only thing grazers have to consider."One of the most interesting results is that grazers in mixed-species groups appear to be making a tradeoff between the risk of being eaten and the need to eat," Beaudrot said.Mixed-species groups were less likely to form when plant productivity was low, she said, which suggests there is a foraging cost associated with mixed-species grazing, said study co-author Meredith Palmer, a behavioral ecologist and postdoctoral fellow at Princeton."These animals face a trade-off," Palmer said. "When different species group together, each individual is less likely to be eaten by a lion than it would be if it were alone or even possibly with its own species. But each individual is also foraging, and if they get further apart they don't have to compete as much for food. As forage becomes more scarce, these animals have to decide whether the extra food they would get from grazing alone is worth the increased danger from lions."The study focuses on a longstanding idea in ecology called the 'stress gradient hypothesis,' which holds that species are more likely to compete with one another when times are good and more likely to benefit each other when they're under stress, Beaudrot said."The hypothesis is supported by the findings from more than 700 plant studies, but it's rarely been applied to animals because mixed-species behavior is rare and there typically aren't enough data about it to draw statistically significant conclusions," she said.The collaboration began when Beaudrot heard Palmer describe the Snapshot Serengeti database in a talk at the 2018 Gordon Research Conference on Predator-Prey Interactions. While mixed-species groups had previously been documented in animals, including primates, cetaceans, ungulates, fish and birds, Palmer and Beaudrot realized that the size of the Snapshot Serengeti camera-trap database would allow them a rare opportunity to not simply observe mixed-species groups but to examine the ecological context within which they occur."Our findings partially support the hypothesis," Beaudrot said. "On the one hand, we found mixed-species groups were more likely to occur when stress was high because of predators, but we also found that mixed-species groups were less likely to form when stress from food scarcity was high, which suggests that stress can also lead to increased competition."She and Palmer said there are also plenty of questions to address with follow-up research, including how mixed-species groups better protects grazers from lions."The larger groups could provide more warning of lions because there are more eyes for vigilance, or that individual species in the group benefit from the behavior of other species in a way that they wouldn't if they had grazed on their own," Palmer said. "Or it could simply be that the odds of any one individual being eaten go down if it's part of a larger group. Our study can't differentiate between any of those mechanisms."
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August 17, 2020
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https://www.sciencedaily.com/releases/2020/08/200817124916.htm
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Flies and mosquitoes beware, here comes the slingshot spider
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Running into an unseen spiderweb in the woods can be scary enough, but what if you had to worry about a spiderweb -- and the spider -- being catapulted at you? That's what happens to insects in the Amazon rain forests of Peru, where a tiny slingshot spider launches a web -- and itself -- to catch unsuspecting flies and mosquitoes.
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Researchers at the Georgia Institute of Technology have produced what may be the first kinematic study of how this amazing arachnid stores enough energy to produce acceleration of 1,300 meters/second2 -- 100 times the acceleration of a cheetah. That acceleration produces velocities of 4 meters per second and subjects the spider to forces of approximately 130 Gs, more than 10 times what fighter pilots can withstand without blacking out.The Peruvian spider and its cousins stand out among arachnids for their ability to make external tools -- in this case, their webs -- and use them as springs to create ultrafast motion. Their ability to hold a ready-to-launch spring for hours while waiting for an approaching mosquito suggests yet another amazing tool: a latch mechanism to release the spring."Unlike frogs, crickets, or grasshoppers, the slingshot spider is not relying on its muscles to jump really quickly," said Saad Bhamla, an assistant professor in Georgia Tech's School of Chemical and Biomolecular Engineering who studies ultrafast organisms. "When it weaves a new web every night, the spider creates a complex, three-dimensional spring. If you compare this natural silk spring to carbon nanotubes or other human-made materials in terms of power density or energy density, it is orders of magnitude more powerful."The study, supported by the National Science Foundation and National Geographic Society Foundation, was published August 17 in the journal Slingshot spiders, known by the scientific genus name Theridiosomatid, build three-dimensional conical webs with a tension line attached to the center. The Peruvian member of that spider family, which is about 1 millimeter in length, pulls the tension line with its front legs to stretch the structure while holding on to the web with its rear legs. When it senses a meal within range, the spider launches the web and itself toward a fly or mosquito.If the launch is successful, the spider quickly wraps its meal in silk. If the spider misses, it simply pulls the tension line to reset the web for the next opportunity."We think this approach probably gives the spider the advantage of speed and surprise, and perhaps even the effect of stunning the prey," noted Symone Alexander, a postdoctoral researcher in Bhamla's lab. "The spiders are tiny, and they are going after fast-flying insects that are larger than they are. To catch one, you must be much, much faster than they are."Slingshot spiders were described in a 1932 publication, and more recently by Jonathan Coddington, now a senior research entomologist at the Smithsonian Institution. Bhamla has an interest in fast-moving but small organisms, so he and Alexander arranged a trip to study the catapulting creature using ultrafast cameras to measure and record the movement."We wanted to understand these ultrafast movements because they can force our perspective to change from thinking about cheetahs and falcons as the only fast animals," Bhamla said. "There are many very small invertebrates that can achieve fast movement through unusual structures. We really wanted to understand how these spiders achieve that amazing acceleration."The researchers traveled six hours by boat from Puerto Maldonado to the Tambopata Research Center. There is no electricity in the area, so nights are very dark. "We looked up and saw a tiny red dot," Bhamla recalled. "We were so far away from the nearest light that the dot turned out to be the planet Mars. We could also see the Milky Way so clearly."The intense darkness raises the question of how the spider senses its prey and determines where to aim itself. Bhamla believes it must be using an acoustic sensing technique, a theory supported by the way the researchers tricked the spider into launching its web: They simply snapped their fingers.Beyond sensing in the dark, the researchers also wondered how the spider triggers release of the web. "If an insect gets within range, the spider releases a small bundle of silk that it has created by crawling along the tension line," Alexander said. "Releasing the bundle controls how far the web flies. Both the spider and web are moving backward."Another mystery is how the spider patiently holds the web while waiting for food to fly by. Alexander and Bhamla estimated that stretching the web requires at least 200 dynes, a tremendous amount of energy for a tiny spider to generate. Holding that for hours could waste a lot of energy."Generating 200 dynes would produce tremendous forces on the tiny legs of the spider," Bhamla said. "If the reward is a mosquito at the end of three hours, is that worth it? We think the spider must be using some kind of trick to lock its muscles like a latch so it doesn't need to consume energy while waiting for hours."Beyond curiosity, why travel to Peru to study the creature? "The slingshot spider offers an example of active hunting instead of the passive, wait for an insect to collide into the web strategy, revealing a further new functionality of spider silk," Bhamla said. "Before this, we hadn't thought about using silk as a really powerful spring."Another unintended benefit is changing attitudes toward spiders. Prior to the study, Alexander admits she had a fear of spiders. Being surrounded by slingshot spiders in the Peruvian jungle -- and seeing the amazing things they do -- changed that."In the rainforest at night, if you shine your flashlight, you quickly see that you are completely surrounded by spiders," she said. "In my house, we don't kill spiders anymore. If they happen to be scary and in in the wrong place, we safely move them to another location."Alexander and Bhamla had hoped to return to Peru this summer, but those plans were cut short by the coronavirus. They're eager to continue learning from the spider."Nature does a lot of things better than humans can do, and nature has been doing them for much longer," she said. "Being out in the field gives you a different perspective, not only about what nature is doing, but also why that is necessary."This research was supported by the National Science Foundation (NSF) through award 1817334 and CAREER 1941933, by the National Geographic Foundation through NGS-57996R-19, and by the Eckert Postdoctoral Research Fellowship from the Georgia Tech School of Chemical and Biomolecular Engineering. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the funding organizations.
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Animals
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August 13, 2020
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https://www.sciencedaily.com/releases/2020/08/200813162809.htm
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Big dogs face more joint problems if neutered early
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Heavier mixed-breed dogs have higher health risks if neutered or spayed early, according to a new study from researchers at the University of California, Davis. The study found mixed-breed dogs weighing more than 44 pounds as adults are at higher risk for one or more joint disorders if neutered before 1 year of age. Dogs weighing up to 43 pounds had no increased risk for joint problems. The study was published in the journal Frontiers in Veterinary Science.
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It's standard practice in the U.S. and much of Europe to neuter dogs by 6 months of age. This study, which analyzed 15 years of data from thousands of dogs at UC Davis Veterinary Medical Teaching Hospital, suggests dog owners should consider their options carefully."Most dogs are mixed breeds," said lead author Benjamin Hart, distinguished professor emeritus at the UC Davis School of Veterinary Medicine. "We hope this study will influence the spay or neuter process in order to give people wishing to adopt a puppy the time to make an informed decision on when to spay or neuter."Researchers examined common joint disorders including hip dysplasia, elbow dysplasia and cranial cruciate ligament tears, a knee injury, in five weight categories. They also looked at risks of mixed-breed dogs developing cancers based on weight but found no increased risk in any weight category compared to intact dogs.The risk of joint disorders for heavier dogs can be up to a few times higher compared to dogs left intact. This was true for large mixed-breed dogs. For example, for female dogs over 43 pounds, the risk jumped from 4 percent for intact dogs to 10-12 percent if spayed before a year of age."The study raises unique challenges," noted co-author Lynette Hart, professor at the UC Davis School of Veterinary Medicine. "People like to adopt puppies from shelters, but with mixed breeds it may be difficult to determine just how big the dog will become if you don't know anything about the dog's parents."Neutering prior to adoption is a common requirement or policy of humane societies, animal shelters and breeders. The authors suggested the policy be reviewed and modified appropriately. Shelters, breeders and humane societies should consider adopting a standard of neutering at over a year of age for dogs that will grow into large sizes.Lynette Hart said the study is especially relevant for people and organizations raising service dogs."They need to take a serious look at this," said Hart. "Joint disorders can shorten a dog's useful working life and impact its role as a family member."A previous study conducted by the UC Davis researchers found health risks based on neuter age varied greatly depending on the breed of the dog.Other authors include Abigail Thigpen with UC Davis School of Veterinary Medicine, and Neil Willits with the Department of Statistics in the UC Davis College of Letters and Science. Research support came from the Center of Companion Animal Health at UC Davis.
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Animals
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August 13, 2020
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https://www.sciencedaily.com/releases/2020/08/200813134551.htm
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Snowshoe hare carcasses feed more then the usual suspects
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What do lynx, flying squirrels, ravens, and wolverines have in common?
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They will all scavenge from snowshoe hare carcasses under the right conditions, according to a new study by University of Alberta ecologists. And they're not alone. In fact, researchers documented 24 different species feeding from snowshoe hare carcasses in Canada's northern boreal forest."This is one of the most diverse scavenger communities recorded," said lead author Michael Peers, who conducted this research during his PhD studies under the supervision of ProfessorStan Boutin in the Department of Biological Sciences."Species we may think of as scavengers like common ravens, magpies, and wolverines were recorded, but also species that people might not expect to be scavengers. We documented snowshoe hares, Canada lynx, red squirrels, Northern flying squirrels, arctic ground squirrels, and chipmunks all scavenging."The researchers examined the northern boreal forest in the Yukon over a four-year period from 2015 to 2018. Using remote sensing cameras, the researchers examined which animals scavenged from nearly 100 opportunistically placed snowshoe hare carcasses throughout the region.The results indicate that prey species may have a more complex impact on food webs than previously thought, because their numbers influence both their direct predators as well as other animals who commonly scavenge."Scavenging by animals can have important impacts on food webs, but is often overlooked in food web research," explained Peers. "Our data shows that a lot of species scavenge in the boreal forest of Canada, and that changing temperatures or the abundance of keystone species can impact scavenging communities."
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Animals
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August 13, 2020
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https://www.sciencedaily.com/releases/2020/08/200813113157.htm
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Ancient genomes suggest woolly rhinos went extinct due to climate change, not overhunting
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The extinction of prehistoric megafauna like the woolly mammoth, cave lion, and woolly rhinoceros at the end of the last ice age has often been attributed to the spread of early humans across the globe. Although overhunting led to the demise of some species, a study appearing August 13 in the journal
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"It was initially thought that humans appeared in northeastern Siberia fourteen or fifteen thousand years ago, around when the woolly rhinoceros went extinct. But recently, there have been several discoveries of much older human occupation sites, the most famous of which is around thirty thousand years old," says senior author Love Dalén, a professor of evolutionary genetics at the Centre for Palaeogenetics, a joint venture between Stockholm University and the Swedish Museum of Natural History. "So, the decline towards extinction of the woolly rhinoceros doesn't coincide so much with the first appearance of humans in the region. If anything, we actually see something looking a bit like an increase in population size during this period."To learn about the size and stability of the woolly rhinoceros population in Siberia, the researchers studied the DNA from tissue, bone, and hair samples of 14 individuals. "We sequenced a complete nuclear genome to look back in time and estimate population sizes, and we also sequenced fourteen mitochondrial genomes to estimate the female effective population sizes," says co-first author Edana Lord, a PhD student at the Centre for Palaeogenetics.By looking at the heterozygosity, or genetic diversity, of these genomes, the researchers were able to estimate the woolly rhino populations for tens of thousands of years before their extinction. "We examined changes in population size and estimated inbreeding," says co-first author Nicolas Dussex, a postdoctoral researcher at the Centre for Palaeogenetics. "We found that after an increase in population size at the start of a cold period some 29,000 years ago, the woolly rhino population size remained constant and that at this time, inbreeding was low."This stability lasted until well after humans began living in Siberia, contrasting the declines that would be expected if the woolly rhinos went extinct due to hunting. "That's the interesting thing," says Lord. "We actually don't see a decrease in population size after 29,000 years ago. The data we looked at only goes up to 18,500 years ago, which is approximately 4,500 years before their extinction, so it implies that they declined sometime in that gap."The DNA data also revealed genetic mutations that helped the woolly rhinoceros adapt to colder weather. One of these mutations, a type of receptor in the skin for sensing warm and cold temperatures, has also been found in woolly mammoths. Adaptations like this suggest the woolly rhinoceros, which was particularly suited to the frigid northeast Siberian climate, may have declined due to the heat of a brief warming period, known as the Bølling-Allerød interstadial, that coincided with their extinction towards the end of the last ice age."We're coming away from the idea of humans taking over everything as soon as they come into an environment, and instead elucidating the role of climate in megafaunal extinctions," says Lord. "Although we can't rule out human involvement, we suggest that the woolly rhinoceros' extinction was more likely related to climate."The researchers hope to study the DNA of additional woolly rhinoceroses that lived in that crucial 4,500-year gap between the last genome they sequenced and their extinction. "What we want to do now is to try to get more genome sequences from rhinos that are between eighteen and fourteen thousand years old, because at some point, surely they must decline," says Dalén. The researchers are also looking at other cold-adapted megafauna to see what further effects the warming, unstable climate had. "We know the climate changed a lot, but the question is: how much were different animals affected, and what do they have in common?"This work was supported by FORMAS, the Swiss National Science Foundation, the Carl Tryggers Foundation, the European Research Council Consolidator Award, and the Knut and Alice Wallenberg Foundation.
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Animals
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August 12, 2020
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https://www.sciencedaily.com/releases/2020/08/200812153639.htm
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Mutations may have saved brown howlers from yellow fever virus
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At the start of her 2008 field season at El Parque El Piñalito in the Misiones province in northeastern Argentina, Ilaria Agostini knew something was terribly wrong. Agostini has studied Misiones' two howler monkey species since 2005 -- brown (
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But the treetops were silent, void of the booming chorus for which the howler monkeys are named."At the beginning, I found one dead monkey. Then in two hours, another one. In all my team and I found 14 dead howlers," said Agostini, a biologist at the Instituto de Biología Subtropical of Argentina. "That first day, we started to suspect it was yellow fever."From 2007 to 2009, a devastating yellow fever virus outbreak nearly decimated El Piñalito's howler monkey populations. The brown and black and gold howlers are extremely susceptible to the disease that enslavers introduced to the Americas. In the last few years, logging activity has progressively affected the howlers' habitat and brought humans closer to wildlife, increasing the risk of virus transmission from the loggers to the howlers. When laboratory analyses confirmed that the monkey's died from yellow fever, health authorities vaccinated human populations to prevent further transmission. By then, the damage was done."Our howler groups just disappeared from the park. We found almost no signs of a presence until 2014 -- six years after the outbreak," Agostini said.A recent United Nations report predicts that more diseases that spread from animals to humans, such as COVID-19, will emerge due to habitat destruction. The flip-side -- human disease spreading to animals -- is also true. How will increased virus transmission affect wild animal populations? The yellow virus outbreak in El Parque El Piñalito provided a natural laboratory to investigate.In a study led by the University of Utah, an international research team tested whether howler monkeys who survived the yellow virus outbreak had any genetic variations that may have kept them alive. The article was published online on June 25, 2020 in the In 2017, Nicole Torosi, postdoctoral researcher at Rutgers University and then a doctoral student at the University of Utah, joined Agostini in El Piñalito to search for any living brown or black and gold howlers. They eventually counted nine brown howlers and two black and gold howlers. Torosin sequenced the genomes of liver samples that Agostini's team had collected from monkeys who died before the outbreak, right after the outbreak, and she extracted DNA from the poop of those who had survived."We saw many more dead black and gold howler monkeys than brown howlers after the outbreak," said Torosin, postdoctoral researcher at Rutgers University. "We wondered if there were genetic differences that may have helped the brown howlers survive somehow."The scientists focused on two immune genes that detect the type of single-stranded RNA viruses to which yellow fever virus belongs. The genes, toll-like receptor (TLR) 7 and TLR 8, recognize and destroy the invading viruses in both humans and non-human primates.The team found no genetic variants present at higher rates in the surviving monkeys than in the deceased ones. However, in comparing the two species, they found three mutations in the DNA sequence of the brown howler individuals. Two of these mutations result in amino acid changes in the part of the protein that detects the disease. In a companion study published in Molecular Phylogenetics and Evolution, Torosin found that the changes were positively selected in the brown howler population."If the amino acid sequence is different, then the protein is different, and that could affect the entire downstream response to dealing with the virus," said Torosin. "Maybe that's why more brown howlers survived."The researchers hypothesize that the brown howlers were exposed to a different virus in the past that selected for the mutations and may have helped them deal with yellow fever virus. Torosin's next steps are to do an immune test for the two species by exposing cells to the virus to see what the responses are in a controlled environment"With COVID-19, we've seen how a virus that originated in China can spread across the world. Here, humans brought a virus to primates that have evolved without exposure to it for tens of millions of years and it nearly wiped them out," said co-author Timothy Webster, anthropologist at the U. "We're interacting with species in new ways that are creating new immune challenges, both for humans and for other species."There are still howler monkeys in the park, but they need time to recover and reorganize into groups -- if they're not wiped by another outbreak, which is a real possibility, Agostini said. In order to document their progress, Agostini and her team of Proyecto Carayá Rojo, together with the NGO Asociación Civil Centro de Investigaciones del Bosque Atlántico (CeIBA), came up with a new way of tracking -- by recording their calls using wildlife acoustic recorders."Just looking for them in the forest isn't efficient. They're so elusive, and live at such low densities, you can go days without finding them," she said. "Recording their vocalizations could be very useful for howlers. They give these very loud calls."
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August 11, 2020
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https://www.sciencedaily.com/releases/2020/08/200811142902.htm
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Primate voice boxes are evolving at rapid pace
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Scientists have discovered that the larynx, or voice box, of primates is significantly larger relative to body size, has greater variation, and is under faster rates of evolution than in other mammals.
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Published in the journal The larynx has three main functions: protecting the airway during feeding, regulating the supply of air to the lungs, and vocal communication. Because of its important role in facilitating social behaviour, through vocalisation, it has long been believed that the larynx is a key area of evolution, particularly in species with highly developed vocal communication systems.The researchers made CT-scans of specimens from 55 different species, and produced 3D computer models of their larynges. These were studied alongside detailed measurements, including body length and body mass.The primates ranged in size from a pygmy marmoset (Cebuella pygmaea) weighing just 110g, to a Western gorilla (Gorilla gorilla) weighing approximately 120kg. The carnivorans spanned from a 280g common dwarf mongoose (Helogale parvula) to a 180kg tiger (Panthera tigris).The study found that, for a given body length, primate larynges are on average 38% larger than those of carnivorans, and that the rate of larynx evolution is faster in these species.There is also more variation in larynx size relative to body size among primates, indicating that primates have greater flexibility to evolve in different ways. Carnivorans follow more of a fixed larynx-size to body-size ratio.Larynx size was also found to be a good predictor of the call frequency of a species, which demonstrates the relevance for vocal communication of the observed size variations.Co-lead author Dr Jacob Dunn, Reader in Evolutionary Biology at Anglia Ruskin University (ARU), said: "This study demonstrates clear differences in the evolution of the larynx between groups of mammals."Specifically, we have shown for the first time that the primate larynx is larger, less closely linked to body size, and under faster rates of evolution than the carnivoran larynx, which is a well-matched comparison group, indicating fundamental differences in the evolution of the vocal organ across species."Co-lead author Dr Daniel Bowling, Instructor in Psychiatry and Behavioral Sciences at Stanford University, added: "Our study also shows that differences in larynx size predict changes in voice pitch, highlighting the larynx's crucial role in vocal communication. This is demonstrated by the rich and varied calls produced by many primate species."The results imply fundamental differences between primates and carnivorans in the forces constraining larynx size, as well as highlighting an evolutionary flexibility in primates that may help explain why they have developed complex and diverse uses of the vocal organ for communication. This provides an exciting avenue for future studies examining variation among other mammalian groups."
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August 11, 2020
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https://www.sciencedaily.com/releases/2020/08/200811120147.htm
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Mathematical patterns developed by Alan Turing help researchers understand bird behavior
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Scientists from the University of Sheffield have used mathematical modelling to understand why flocks of long-tailed tits segregate themselves into different parts of the landscape.
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The team tracked the birds around Sheffield's Rivelin Valley which eventually produced a pattern across the landscape, using maths helped the team to reveal the behaviours causing these patterns.The findings, published in the It was previously unknown why flocks of long-tailed tits live in separate parts of the same area, despite there being plenty of food to sustain multiple flocks and the birds not showing territorial behaviour.The equations used to understand the birds are similar to those developed by Alan Turing to describe how animals get their spotted and striped patterns. Turing's famous mathematics indicates if patterns will appear as an animal grows in the womb, here it's used to find out which behaviours lead to the patterns across the landscape.Territorial animals often live in segregated areas that they aggressively defend and stay close to their den. Before this study, these mathematical ideas had been used to understand the patterns made by territorial animals such as coyotes, meerkats and even human gangs. However, this study was the first to use the ideas on non-territorial animals with no den pinning them in place.Natasha Ellison, PhD student at the University of Sheffield who led the study, said: "Mathematical models help us understand nature in an extraordinary amount of ways and our study is a fantastic example of this.""Long-tailed tits are too small to be fitted with GPS trackers like larger animals, so researchers follow these tiny birds on foot, listening for bird calls and identifying birds with binoculars. The field work is extremely time consuming and without the help of these mathematical models these behaviours wouldn't have been discovered."
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August 12, 2020
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https://www.sciencedaily.com/releases/2020/08/200812201330.htm
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Fireflies shed light on the function of mitochondria
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Tiny factories float inside our cells and provide them with almost all the energy they need: the mitochondria. Their effectiveness decreases when we get older, but also when we face many diseases such as diabetes, cancer or Parkinson's. This is why scientists are increasingly interested in how they work. At EPFL, a team has developed a protocol to measure their activity live in living animals. Described in
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Mitochondria are almost like cells within the cell. Like their host, they have a membrane that protects their genetic material and, above all, filters exchanges with the outside. The difference in electrical charge between the inside and the outside of the mitochondria, called "membrane potential," allow certain molecules to go through, while other remain at bay.As between the two poles of a used electric battery, the membrane potential of the mitochondria can sometimes drop. For scientists, this is an unmistakable clue that its functions are impaired.We know how to measure the phenomenon on cultured cells. But until now, you couldn't really see it on live animals. "Cell cultures are not very effective in studying diseases linked to mitochondria," explains Elena Goun, professor at EPFL.Elena Goun and her colleagues have found a way to study the phenomenon in live mice. They use animals that are genetically modified to express luciferase -- an enzyme that produces light when combined with another compound called luciferin. This is how fireflies sometimes light up our summer evenings.Scientists have developed two molecules that, when injected into the rodent, pass into the mitochondria, where they activate a chemical reaction. The mitochondria then produce luciferin and eject it outwards. Luciferin combines with luciferase in the mice's cells and produce light."In a completely darkened room, you can see the mice glowing, just like fireflies," says Elena Goun.Researchers need only measure light intensity to get a clear picture of how well the mitochondria are functioning. When they function less well, their membrane lets in less chemical compounds. The production of luciferin decreases, and therefore the luminosity too.To demonstrate the potential of their method, the researchers carried out several experiments. For example, they observed that older rodents produce significantly less light. This drop in light reflects a drop in the activity of mitochondria -- their membrane potential is much lower than in younger rodents. We know that age causes a decrease in the activity of mitochondria, but this is the first time that the phenomenon has been accurately measured directly in living animals.The team also tested a chemical known to rejuvenate mitochondria: nicotinamide riboside. This molecule is non-toxic and commercially available as a dietary supplement. Mice given this compound produced more light, a sign of increased mitochondrial activity.The researchers were also able to measure the same phenomenon in animal models of cancer. This could be of great help for anticancer drug research. In addition, they also successfully demonstrated monitoring of mitochondria membrane potential in cells of brown adipose tissue, rich in mitochondria. Its stimulation could help cure certain forms of obesity.The method described by Elena Goun is primarily intended for scientists who want to better understand the role of mitochondria and who need an animal model. The field of application is wide: diabetes, oncology, aging, nutrition, neurogenerative diseases... "Our process can measure varying degrees of mitochondria activity, and not just an on / off signal," explains Elena Goun. "It is extremely sensitive -- much more than a PET scan -- affordable and easy to implement.
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August 10, 2020
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https://www.sciencedaily.com/releases/2020/08/200810141008.htm
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Coronavirus transmission risk increases along wildlife supply chains
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Coronaviruses were detected in a high proportion of bats and rodents in Viet Nam from 2013 to 2014, with an increasing proportion of positive samples found along the wildlife supply chain from traders to large markets to restaurants, according to a study published August 10 in the open-access journal PLOS ONE by Amanda Fine of the Wildlife Conservation Society and colleagues. As noted by the authors, the amplification of coronaviruses along the wildlife supply chain suggests maximal risk for end consumers and likely explains the coronavirus spillover to people.
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Outbreaks of emerging coronaviruses in the past two decades and the current pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlight the importance of this viral family as a public health threat. Human-wildlife contact with a bat or an intermediate host species in China almost certainly triggered a coronavirus spillover event that may have involved wildlife markets and led to the pandemic spread of SARS-CoV-2, according to the latest scientific evidence. Beyond China, commercial wildlife farming in Viet Nam is part of the expanded international wildlife trade that is thought to contribute to global epidemics, such as SARS and now coronavirus disease 2019 (COVID-19), which is caused by SARS-CoV-2.To better understand the natural hosts of coronaviruses and the risk for these wildlife-human interfaces to facilitate spillover into humans, Fine and her collaborators investigated presence of viruses in the coronavirus family and diversity in wildlife at wildlife-human interfaces in Viet Nam from 2013 to 2014 (years prior to the emergence of SARS-CoV-2).They observed high proportions of positive samples of coronaviruses among field rats (34.0%, 239/702) destined for human consumption and bats in guano farms (74.8%, 234/313) adjacent to human dwellings. The odds of coronavirus detection increased along the supply chain, from field rats sold by traders (20.7%, 39/188), to field rats sold in large markets (32.0%, 116/363), and field rats served in restaurants (55.6%, 84/151). Coronaviruses were also detected in rodents on most wildlife farms sampled (60.7%, 17/28), affecting Malayan porcupines (6.0%, 20/331) and bamboo rats (6.3%, 6/96) raised for human consumption. To minimize the public health risks of viral disease emergence, the authors recommend improving coronavirus surveillance in wildlife and implementing targeted wildlife trade reform.The authors add: "This study shows the wildlife supply chain generates a one-two punch when it comes to spillover risk. It is known to increase contact rates between wildlife and people and here we show how it greatly amplifies the number of infected animals along the way."
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August 10, 2020
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https://www.sciencedaily.com/releases/2020/08/200810113202.htm
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An ancient association? Crickets disperse seeds of early-diverging orchid Apostasia nipponica
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Associate Professor SUETSUGU Kenji (Kobe University Graduate School of Science) presents evidence of the apparently unusual seed dispersal system by crickets and camel crickets in
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Seed dispersal is a key evolutionary process and a central theme in terrestrial plant ecology. Animal-mediated seed dispersal, most frequently by birds and mammals, benefits seed plants by ensuring efficient and directional transfer of seeds without relying on random abiotic factors such as wind and water. Seed dispersal by animals is generally a coevolved mutualistic relationship in which a plant surrounds its seeds with an edible, nutritious fruit as a good food for animals that consume it . Birds and mammals are the most important seed dispersers, but a wide variety of other animals, including turtles and fish, can transport viable seeds. However, the importance of seed dispersal by invertebrates has received comparatively little attention. Therefore, discoveries of uncommon mechanisms of seed dispersal by invertebrates such as wetas, beetles and slugs usually evoke public curiosity toward animal-plant mutualisms.Unlike most plants, all of the >25,000 species of orchids are heterotrophic in their early life history stages, obtaining resources from fungi before the production of photosynthetic leaves. Orchid seeds, therefore, contain minimal energy reserves and are numerous and dust-like, which maximizes the chance of a successful encounter with fungi in the substrate. Despite considerable interest in the ways by which orchid flowers are pollinated, little attention has been paid to how their seeds are dispersed, owing to the dogma that wind dispersal is their predominant strategy. Orchid seeds are very small and extremely light, and are produced in large numbers. These seeds do not possess an endosperm but instead usually have large internal air spaces that allow them to float in the air column. In addition, orchid seeds are usually winged or filiform, evolved to be potentially carried by air currents. Furthermore, most orchid seeds have thin papery coats formed by a single layer of non-lignified dead cells. It has been thought that these fragile thin seed coats cannot withstand the digestive fluids of animals, in contrast to the thick seed coats in indehiscent fruits, which are considered an adaptation for endozoochory.However, it is noteworthy that the subfamily Apostasioideae commonly has indehiscent fruits with hard, crustose black seed coats. Apostasioids are the earliest-diverging subfamily of orchids and consist of only two genera (Here Suetsugu has studied the Orchid seeds lack a definitive fossil record due to their extremely minute size. Therefore, the interaction described here provides some important clues as to the animals that may have participated in the seed dispersal of the ancestors of orchids. Given that the origin of crickets and camel crickets precedes the evolution of orchids, they are among the candidates for seed dispersers of the ancestors of extant orchids. Owing to many plesiomorphic characteristics and the earliest-diverging phylogenetic position, members of Apostasioideae have been extensively studied to understand their floral structure, taxonomy, biogeography, and genome. However, there is still a lack of information regarding seed dispersal in the subfamily. Therefore, Suetsugu has documented the animal-mediated seed dispersal of Apostasioideae members for the first time. Whether seed dispersal by animals (and particularly by orthopteran fruit feeders) is common in these orchids warrants further investigation. It is possible that this method of dispersal is an ancestral trait in Apostasioideae, given that indehiscent fruits with a hard seed coat are common within the clade. Further research, such as an ancestral character-state reconstruction analysis of more data on the seed dispersal systems of other apostasioids, can provide deeper insights into the early evolution of the seed dispersal system in
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August 10, 2020
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https://www.sciencedaily.com/releases/2020/08/200810103229.htm
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Key to harmonious pet relationships: Pheromones
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Animal behaviour scientists from the University of Lincoln, UK, have discovered that filling your home with appeasing pheromones could be the key to a happy household where both dogs and cats are living under the same roof.
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The new research, led by Professor Daniel Mills and Dr Miriam Prior, explored the effects of two different pheromone products on cat-dog interactions in homes where owners could see room for improvement in their pets' relationships.Their new scientific paper is now available to read online via the journal The results show that both products used -- Feliway Friends, which emits pheromones that are calming for cats, and Adaptil, which does the same for dogs -- both had a positive impact on the interactions between cats and dogs living in the same home.Over a six week period, both products led to a notable decrease in undesirable interactions -- such as dog chasing cat, cat hiding from dog, cat and dog staring at each other, and dog barking at cat. Users of Adaptil even observed a significant increase in some desirable behaviours -- friendly greetings between cat and dog, and time spent relaxing in the same room."Although we are all aware of the perceived tensions between cats and dogs, we believe this is the first study of its kind to explore the use of pheromone products to improve the relationship when the two species are living in the same household," explained Professor Mills, Professor of Veterinary Behavioural Medicine in Lincoln's School of Life Sciences."Seven per cent of households in the UK own both a cat and a dog, which represents a large number of pet owners and their animals living with potentially stressful animal relationships on a day-to-day basis. Many cat and dog owners report that their animals are comfortable in each other's' company, but where this isn't the case, a poor relationship between a resident cat and dog can have serious consequences for the welfare of individual animals. There may be an unacceptable level of social stress or restricted access to key resources such as food, water or suitable toilet areas. There will also be increased stress for the remainder of the family (both human and animal), and potential risks of injury due to conflict."It has also been reported that a problematic relationship between a new pet and an existing pet is one of the main reasons for cats and dogs being taken to shelters for rehoming.The pet owners involved in this new scientific trial reported weekly on the frequency of 10 specific undesirable interactions and seven specific desirable interactions between their cats and dogs. They were split into two groups; one group using Feliway Friends and the other using Adaptil, with the pheromones supplied in unlabelled packaging and randomly assigned by an independent staff member such that neither the participants nor the researchers knew which product was being trialled in each household until after the statistics had been collected.The researchers were aware that in many households, the comfortability of the cat seems to have a stronger influence over the quality of the cat-dog relationship. It could therefore be seen as surprising that it was the product releasing dog pheromones which was seen to increase specific desirable interactions.Miriam, a Lincoln-based vet who undertook the work as part of her postgraduate degree in Clinical Animal Behaviour at the University of Lincoln, said: "While it might be expected that Feliway Friends would be more effective in multi-species homes given the apparently stronger contribution of the cat's comfortability to the quality of the cat-dog relationship, this did not appear to be the case. Our results might be explained by the behaviour of the dog being the primary determinant of the cat's quality of interaction with it."We would like to investigate this further to really tease out the effects of these pheromone products individually and also to investigate their use in combination with each other. We suggest that Adaptil may have had such a beneficial effect because a more relaxed dog may be less likely to disturb the cat (e.g. by chasing it), resulting in a cat that is less stressed and more willing to form some form of social bond with the dog."
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August 10, 2020
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https://www.sciencedaily.com/releases/2020/08/200810103310.htm
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Biodiversity may limit invasions: Lessons from lizards on Panama Canal islands
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When the U.S. flooded Panama's Chagres River valley in 1910, Gatun Lake held the record as the world's biggest reservoir. This record was surpassed, but researchers at the Smithsonian Tropical Research Institute (STRI), who are now studying invading lizards on the tiny islands that dot the lake, discovered that islands with native lizards act as another kind of reservoir, harboring the parasites that control invaders. The study, published in the journal
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As part of another study to find out how many generations it takes for slender anole lizards (When they came back several times during the next two years to see how the lizards were doing in their new habitats, they recounted the number of mites."We found that on the islands with no resident species of anole lizard, the slender anole lizards that were transplanted to the islands lost their mites within a single generation, and the mites are still gone several generations later (up until the present)," Cox said. "Indeed, individual founding lizards that had mites during the initial transplant had no mites when they were later recaptured. In contrast, anole lizards that were transplanted to an island with another resident (native) species of anole lizard kept their mites for three generations, and some of the founders on the two-species island never lost their mites.""Our study turned out to be a large-scale experimental test of the enemy release hypothesis," said Logan, who did this work as a three-year STRI/Tupper postdoctoral fellow. "Often, when an invasive animal shows up in a new place, all of its pathogens and parasites are left behind or do not survive, giving it an extra survival advantage in the new place: thus the term enemy release."The team also found that the two-species island had lower density and lower biomass per unit area of the invasive lizard species, indicating that the continued presence of the mites may be keeping their populations under control."Our study is a clear example of something that conservationists have been trying to communicate to the public for some time," Logan said. "Diverse native communities sometimes function as 'enemy reservoirs' for parasites and diseases the keep down the numbers of invaders."Funding for this study was provided by the Smithsonian Institution, Georgia Southern University, the Theodore Roosevelt Memorial Foundation and the American Museum of Natural History.
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August 6, 2020
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https://www.sciencedaily.com/releases/2020/08/200806203703.htm
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1 in 4 UK puppies may be being acquired before minimum recommended age
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One in four puppies in the UK may be being acquired before the recommended minimum age -- a figure that is considerably higher than what has been reported before -- suggests research published in the latest edition of
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Separating a puppy from its mother too early may have long-term consequences on physiological and behavioural development that risks behavioural problems later in life, a major reason why dogs are given up or left in shelters, warns the author of a linked comment.In the UK many welfare and veterinary organisations, such as the Animal Welfare Foundation, Blue Cross, PDSA and the Dogs Trust, recommend that puppies shouldn't be separated from their mothers until they are at least 8 weeks (56 days) old. There are legal restrictions on selling a puppy under this age in the UK.Their guidance also recommends that prospective buyers should view the puppy with its mother, and this has been enshrined in English law since 2018.The researchers wanted to find out if particular factors were associated with the acquisition of puppies under the age of 8 weeks and without viewing the puppy's mother.They drew on data for 2392 puppies collected between May 2016 and February 2019 as part of 'Generation Pup', a long term UK study of dog health, behaviour, and welfare.The data were obtained from three questionnaires, with details around the process of acquisition completed by owners before or after they had acquired their puppy. In all, 1844 puppies were eligible for inclusion in the final analysis.The responses showed that 1 in 4 (461) puppies had been acquired before they were 8 weeks old, a proportion that is considerably higher than what has been reported before. Around 1 in 12 (149; just over 8%) had been acquired without viewing the puppy's mother. Just 30 (just over 1.5%) had been acquired under 8 weeks of age and without viewing the mother.Five factors were independently associated with acquisition of an 'under age' puppy.Owners who visited their puppy at least once before taking it home were more likely to acquire the animal before it was 8 weeks old. This might be because they couldn't bear to leave without taking the puppy home, or because they felt the puppy was old enough, suggest the researchers, by way of an explanation.Owners who intended to use their puppy as a working dog, such as for herding animals, pest control, work in the police or military, as a search and rescue, or guard dog were also more likely to acquire their puppy before it was 8 weeks old. This might be because they wanted to start training the puppy as soon as possible, say the researchers.The analysis also revealed that the odds of early acquisition increased in tandem with the number of dogs already in the household and if the dog was a mix of unknown breeds."Mixed breed puppies may be more likely to have been bred by a hobby breeder than a licensed breeder, or be a result of accidental mating," suggest the researchers. "Hobby breeders do not need to conform to the same selling restrictions as licensed breeders."At the other end of the spectrum, the likelihood of acquiring a puppy under the recommended age fell as the level of annual household income rose.Similarly, owners who visited their puppy before taking it home, or bought a puppy registered with the Kennel Club, or who viewed the puppy's father and/or collected the puppy from the breeder's home, had lower odds of acquiring a puppy without viewing the mother.The researchers suggest that prospective owners may be more aware of the recommendations to view the puppy with its mother than those around the recommended minimum age.Their findings might help target specific owners, "with educational or media campaigns that could decrease the proportion of puppies acquired in this way in the future," they conclude.In a linked research comment, vet Dr Federica Pirrone, University of Milan, Italy, emphasised the importance of the guidance and regulations."Early separation of a puppy from its mother and littermates is a husbandry strategy that may increase the animal's chances of exhibiting potentially problematic behaviours as an adult," she warns."The occurrence of problematic behaviours is the most common reason why dogs are relinquished, abandoned or, in countries where it is allowed, even euthanased."Early separation impairs early brain development which restricts the ability of puppies to adapt to new stimuli and to develop good social skills as adults. They are highly likely to exhibit fear and anxiety-related behaviours as adults, which are then often perceived by owners as problematic, she explains.Similarly, she emphasises: "Seeing the mother before buying a puppy enables the prospective owner to ascertain that she is unstressed and free from behavioural problems, which in turn helps predict that the puppy will not develop behavioural problems later in life.""It is, therefore, essential to encourage prospective owners to be well informed regarding dog behaviour and to be aware of the importance of correct socialisation," she says.Daniella Dos Santos, British Veterinary Association President, commented: "There are very good reasons why puppies shouldn't leave their mother before they're eight weeks old. Rehoming from this age means puppies are fully and correctly weaned, and staying with their mother in early development plays a vital role in social and behavioural development."Prospective puppy buyers should always ask to view them alongside their mother first and we strongly recommend using the free Puppy Contract to make sure that they're getting a happy, healthy and well-socialised animal from a reputable breeder or rehoming centre."
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Animals
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August 6, 2020
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https://www.sciencedaily.com/releases/2020/08/200806153617.htm
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Study finds high levels of toxic pollutants in stranded dolphins and whales
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A study led by researchers at Florida Atlantic University's Harbor Branch Oceanographic Institute examined toxins in tissue concentrations and pathology data from 83 stranded dolphins and whales along the southeastern coast of the United States from 2012 to 2018. Researchers examined 11 different animal species to test for 17 different substances in animals found on the shores in North Carolina and Florida.
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This is the first study to date to publish a report examining concentrations in blubber tissues of stranded cetaceans of atrazine, an herbicide, DEP, (a phthalate ester found in plastics), NPE or nonylphenol ethoxylate commonly used in food packing, and triclosan, an antibacterial and antifungal agent present in some consumer products, including toothpaste, soaps, detergents and toys.The study also is the first to report concentrations of toxicants in a white-beaked dolphin and in Gervais' beaked whales, species for which the scientific literature remains sparse. Documenting toxicants in cetaceans is a critical step in tracing chemical contaminants within the marine food web and understanding their effects on biological systems.For the study, just published in the journal Results of the study showed that toxin and element concentrations varied based on animal demographic factors including species, sex, age and location. Liver samples from bottlenose dolphins had significantly higher average concentrations of lead, manganese, mercury, selenium, thallium, and zinc, and lower average concentrations of NPE, arsenic, cadmium, cobalt, and iron than samples from pygmy sperm whales. In adult female bottlenose dolphins, average arsenic concentrations were significantly higher and iron concentrations were significantly lower than in adult males. Adult bottlenose dolphins had significantly higher average concentrations of lead, mercury, and selenium, and significantly lower average manganese concentrations compared to juveniles.Geography also had an impact. Dolphins that stranded in Florida had significantly higher average concentrations of lead, mercury, and selenium, and lower concentrations of iron than dolphins that stranded in North Carolina.Toxicants in the marine environment result from polluted runoff and chemicals in waterways from fossil fuels as well as single-use plastics commonly used by humans. These plastic objects include packaging film, detergents and some children's toys and contain dangerous phthalates."We must do our part to reduce the amount of toxicants that enter into our marine environment, which have important health and environmental implications not just for marine life but for humans," said Page-Karjian. "These chemicals work their way up through the food chain and get more concentrated the higher up they go. When dolphins and whales eat fish with concentrations of the chemicals, the toxic elements enter their bodies. Dolphins eat a variety of fish and shrimp in these marine environments and so do humans."
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August 6, 2020
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https://www.sciencedaily.com/releases/2020/08/200806111854.htm
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This fruit attracts birds with an unusual way of making itself metallic blue
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There's a reason why blue fruits are so rare: the pigment compounds that make fruits blue are relatively uncommon in nature. But the metallic blue fruits of Viburnum tinus, a popular landscaping plant in Europe, get their color a different way. Instead of relying solely on pigments, the fruits use structural color to reflect blue light, something that's rarely seen in plants. Researchers reporting August 6 in the journal
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"Structural color is very common in animals, especially birds, beetles, and butterflies, but only a handful of plant species have ever been found to have structural color in their fruits," says co-first author Miranda Sinnott-Armstrong, a postdoctoral researcher at the University of Colorado-Boulder. "This means that V. tinus, in addition to showing a completely novel mechanism of structural color, is also one of the few known structurally colored fruits."Senior author Silvia Vignolini, a physical chemist at the University of Cambridge, has been interested in the plants for nearly 10 years. "I actually found this Viburnum in a garden in Italy and observed that they looked weird, so we measured them at the time but didn't have conclusive results. It was kind of always on the back of my mind," she says. As her team grew, they become more interested in V. tinus and eventually had the capability to examine the structure of the fruits using electron microscopy. "Before we got the images, we were just seeing all these blobs," she says. "When we found out that those blobs were lipids, we got very excited."While most plants have cell walls made of cellulose, used to make cotton and paper, V. tinus fruit cells have much thicker walls with thousands of globular lipids arranged in layers that reflect blue light. The structure formed by this so-called lipid multilayer allows the fruits to create their vibrant blue color while containing no blue pigment. "This is very strange because globular lipids like these are not usually found in this arrangement in the cell wall, as they are normally stored inside the cell and used for transport," says co-first author Rox Middleton, a physicist who studied the optical response of the fruits during her PhD and is now a postdoctoral researcher at the University of Bristol. "We also believe that this lipid may contribute to the fruit's nutrition. That means that the fruit can demonstrate how nutritious it is by being a beautiful, shiny blue."This extra nutrition would be important for V. tinus's main consumers: birds that disperse the plant's seeds. Although the researchers can't say for sure whether the lipids are used as fat by the birds that consume them, there is reason to believe they might be. If so, the researchers suggest that the metallic blue color made by the lipid multilayer could indicate to the birds that if they see this striking blue, the fruit in question will have enough nutrients to make it a worthwhile meal. "While birds have been shown to be attracted to blue fruits," says Vignolini, "other blue fruits that we have studied essentially don't have any nutritional value."Going forward, the researchers want to see how widespread blue structural color is in fruits to understand its ecological significance. They had never seen this type of lipid multilayer in a biomaterial before, but since their discovery, they've begun to take notice of other species. "We actually realize now that there are some older electron microscopy pictures from other plants where you can see the blobs. The researchers didn't know that they were lipids at the time, or that lipids could even form this type of structure, but our research suggests that they very well could be, meaning this structure may not be limited to Viburnum," Vignolini says.Additionally, learning how V. tinus can use such a unique mechanism to make color may have implications for how we color our own foods. "There are lots of problems connected to food coloration," says Vignolini. She adds that once this mechanism is better understood, it could potentially be used to create a healthier, more sustainable food colorant.But right now, Vignolini is just excited her initial hunch paid off: "I've been working on this type of photonic structure for quite a while, and I was beginning to think there were no new ways to make it -- at some point you've seen so many that you think, 'This is more or less the end, it's going to be difficult to find something new,'" she says. "Instead, we discovered much more than what we expected."
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August 6, 2020
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https://www.sciencedaily.com/releases/2020/08/200806111849.htm
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Fossil mystery solved: Super-long-necked reptiles lived in the ocean, not on land
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A fossil called
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"I've been studying "In the same region where many of the big To solve these two long-standing mysteries, the researchers used newer technologies to see details of the animals' bones. The large "The power of CT scanning allows us to see details that are otherwise impossible to observe in fossils," says Spiekman. "From a strongly crushed skull we have been able to reconstruct an almost complete 3D skull, revealing crucial morphological details."The skulls had key features, including nostrils on top of the snout like a crocodile's, that suggested Rieppel wasn't surprised that evidence pointed to a water-dwelling So that answered one question, about where "We looked at cross sections of bones from the small type and were very excited to find many growth rings. This tells us that these animals were mature," says Torsten Scheyer, the study's senior author and a researcher at University of Zurich."The small form is an adult, which basically sealed the case," says Rieppel. "It's proven now that these are two species." The researchers named the larger one "For many years now we have had our suspicions that there were two species of The animals' different sizes, along with cone-shaped teeth in the big species and crown-shaped teeth in the little species, meant they probably weren't competing for the same prey."These two closely related species had evolved to use different food sources in the same environment," says Spiekman. "The small species likely fed on small shelled animals, like shrimp, in contrast to the fish and squid the large species ate. This is really remarkable, because we expected the bizarre neck of This "splitting up" of a habitat to accommodate two similar species is called niche partitioning. "Darwin focused a lot on competition between species, and how competing over resources can even result in one of the species going extinct," says Rieppel. "But this kind of radical competition happens in restricted environments like islands. The marine basins that "
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August 6, 2020
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https://www.sciencedaily.com/releases/2020/08/200806111839.htm
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Why the 'wimpy' Y chromosome hasn't evolved out of existence
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Much smaller than its counterpart, the X chromosome, the Y chromosome has shrunken drastically over 200 million years of evolution. Even those who study it have used the word "wimpy" to describe it, and yet it continues to stick around even though sex chromosomes in non-mammalian vertebrates are known to experience quite a bit of evolutionarily turnover. An Opinion paper publishing on August 6 in the journal
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"The Y chromosome is generally thought to be protected from extinction by having important functions in sex determination and sperm production, which, if moved to somewhere else in the genome, would signal its demise," says co-author Paul Waters, a professor at the University of New South Wales in Sidney, Australia. "However, we propose that the future of the Y chromosome is secure because it carries executioner genes that are critical for successful progression of male meiosis -- and unlike other genes on the Y, these executioners self-regulate."During meiosis, sexually reproducing organisms form haploid gametes (eggs and sperm), each of which contains only one copy of each chromosome. They do this through one round of genome replication followed by two consecutive rounds of cell division. This meiotic process is tightly regulated to avoid infertility and chromosome abnormalities.One step of meiosis requires the silencing of both the X and Y chromosomes during a specific window. "Importantly, the Y chromosome bears genes that regulate this process, a feature that has been known for years now," says co-author Aurora Ruiz-Herrera, a professor at Universitat Autònoma de Barcelona in Spain. "We believe that bearing these genes is what protects the Y chromosome from extinction. The genes that regulate the silencing process, the Zfy genes, are called 'executioner' genes. When these genes are turned on at the wrong time and at the wrong place during meiosis, they are toxic and execute the developing sperm cell. They essentially act as their own judge, jury, and executioner, and in doing so, protect the Y from being lost."The Y chromosome is present in all but a handful of mammalian species. Important contributions to understanding the Y chromosome have come from looking at the rare mammals that don't follow the rules -- for example, a handful of species of rodents. "I've always been a firm believer that the comparison of unusual systems is informative to other systems," Waters says. "Determining the common prerequisites for rare Y chromosome loss enabled us to build a hypothesis for how Y chromosomes persist in most species."The collaboration between Waters and Ruiz-Herrera -- based half a world apart -- began to bear fruit during the COVID-19 pandemic. "Earlier this year, we put together a grant application to examine aspects of X chromosome silencing during meiosis," says Waters. "After the shutdown of our labs, we decided to massage our discussions into a review article. We had no idea we would essentially stumble onto such an intuitive mechanism to explain why the mammal Y chromosome has persisted in most species." Going forward, the researchers plan to take a closer look at how the executioner genes evolved and to look at how they are regulated from evolutionary and functional perspectives."The mammalian Y has been taken as a symbol of masculinity, not only in popular culture but also in the scientific community," Ruiz-Herrera says. "Despite that, many have projected that, given enough time, it will be eventually lost. However, we propose the Y chromosome can escape this fatal fate. So our male colleagues can breathe easy: the Y will persist!"
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August 5, 2020
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https://www.sciencedaily.com/releases/2020/08/200805160949.htm
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Herbivores most at risk of extinction
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One million years ago, the extinction of large-bodied plant-eaters changed the trajectory of life on Earth. The disappearance of these large herbivores reshaped plant life, altered fire regimes across Earth's landscapes, and modified biogeochemical cycling in such a way that Earth's climate became slightly colder. A new study out today by Utah State University Assistant Professor of Watershed Sciences, Trisha Atwood, suggests that modern-day megaherbivores (plant-eaters weighing more than 1000 kg) could soon suffer the same fate as their ancient ancestors, with unknown consequences for Earth and all of its inhabitants.
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Armed with a dataset of the diets of over 24,500 mammals, birds, and reptiles, Atwood and her team set out to answer the question "Are plant-eaters, meat-eaters, or animals who eat both plants and meat, at the greatest risk of extinction?" Their findings, published in the journal The results indicate that with over a quarter of the world's modern-day herbivores threatened with extinction, plant eaters have the highest representation of at-risk species in the present day. The study also highlights that this attack on herbivores is not a new phenomenon. Human activities have led to the disproportionate extinction of herbivores compared to predators since at least the late Pleistocene (11,000-50,000 years ago)."The results were somewhat shocking," said Atwood. "Our highly publicized and fraught relationship with predatory animals such as lions and wolves has led to the unfounded perception that we are losing predators more than any other trophic group."Using evidence-based science to challenge misconceptions like the one Atwood's team uncovered is essential for getting society on the right track towards addressing future extinctions. Because a species' role in its ecosystem is intricately linked to what it eats, understanding whether predators, herbivores, or omnivores are at the highest risk of extinction helps scientists and society understand what the potential consequences of losing those species are.Already the consequences of declines in modern herbivores from land-use change and hunting have begun to echo those that occurred on Earth 1 million years ago; alterations to plant life, changes to fire regimes, and disruptions to nutrient cycling. This study highlights that we must redouble our efforts to strategically invest in conservation and management of herbivores to avoid future dramatic changes in the functions arising from animals at the base of global foodwebs.Although the results of the study indicate that herbivores are the most at-risk group, it is not clear sailing for predators. The study also identified scavengers, which eat the remains of recently deceased animals (e.g., vultures) and animals that primarily eat fish, such as seabirds, as having a heightened risk of extinction."Our results enable us to identify specialized diets within the carnivores that are associated with higher extinction risk, and also identify the habitats these species live in," says Edd Hammill an Assistant Professor of Watershed Sciences at Utah State University and co-author of the study. "It would appear that seabirds across the globe suffer disproportionately high levels of extinction"To better inform conservation actions, the researchers are now wrestling to understand what it is about herbivores, scavengers, and piscivores (animals that consume fish) that make them more susceptible to extinction compared to other animals."Documenting a pattern in extinctions is only the first step towards curbing the loss of species," says Atwood. "Our next step is to understand the intricacies of why this pattern is occurring; only then will we really have a chance at stopping these future extinctions."
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August 5, 2020
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https://www.sciencedaily.com/releases/2020/08/200805124044.htm
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Dinosaur relative's genome linked to mammals: Curious genome of ancient reptile
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A lizard-like creature whose ancestors once roamed the Earth with dinosaurs and today is known to live for longer than 100 years may hold clues to a host of questions about the past and the future.
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In a study published Aug. 5 in "We found that the tuatara genome has accumulated far fewer DNA substitutions over time than other reptiles, and the molecular clock for tuataras ticked at a much slower speed than squamates, although faster than turtles and crocodiles, which are the real molecular slowpokes," said co-author Marc Tollis, an assistant professor in the School of Informatics, Computing, and Cyber Systems at Northern Arizona University. "This means in terms of the rate of molecular evolution, tuataras are kind of the Toyota Corolla -- nothing special but very reliable and persistently ticking away over hundreds of millions of years."Tuatara have been out on their own for a staggering amount of time, with prior estimates ranging from 150-250 million years, and with no close relatives the position of tuatara on tree of life has long been contentious. Some argue tuatara are more closely related to birds, crocodiles and turtles, while others say they stem from a common ancestor shared with lizards and snakes. This new research places tuatara firmly in the branch shared with lizards and snakes, but they appear to have split off and been on their own for about 250 million years -- a massive length of time considering primates originated about 65 million years ago, and hominids, from which humans descend, originated approximately six million years ago."Proving the phylogenetic position of tuatara in a robust way is exciting, but we see the biggest discovery in this research as uncovering the genetic code and beginning to explore aspects of the biology that makes this species so unique, while also developing new information that will help us better conserve this taonga or special treasure," said lead author Neil Gemmell, a professor at the University of Otago.One area of particular interest is to understand how tuataras, which can live to be more than 100 years old, achieve such longevity. Examining some of the genes implicated in protecting the body from the ravages of age found that tuatara have more of these genes than any other vertebrate species thus far examined, including humans. This could offer clues into how to increase humans' resistance to the ailments that kill humans.But the genome, and the tuatara itself, has so many other unique features all on its own. For one, scientists have found tuatara fossils dating back 150 million years, and they look exactly the same as the animals today. The fossil story dates the tuatara lineage to the Triassic Period, when dinosaurs were just starting to roam the Earth."The tuatara genome is really a time machine that allows us to understand what the genetic conditions were for animals that were vying for world supremacy hundreds of millions of years ago," he said. "A genome sequence from an animal this ancient and divergent could give us a better idea about what the ancestral amniote genome might have looked like."While modern birds are the descendants of dinosaurs, they are less suitable for this type of research because avian genomes have lost a significant amount of DNA since diverging from their dinosaur ancestors.But the tuataras, which used to be spread throughout the world, have other unusual features. Particularly relevant to this research is the size of its genome; the genome of this little lizard has 5 billion bases of DNA, making it 67 percent larger than a human genome. Additionally, tuataras have temperature-based sex determination, which means the ratio of males to females in a clutch of eggs depends on the temperatures at which they are incubated. They also have a pronounced "third eye" -- a light sensory organ that sticks through the top of their skulls. Mammals' skulls have completely covered the third eye, though they still contain the pineal gland underneath, which helps maintain circadian rhythms.The tuatara also is unique in that it is sacred to the M?ori people. This research, for all the scientific knowledge that came from it, was groundbreaking for its collaboration with the Indigenous New Zealanders. The purpose was to ensure the research aligned with and respected the importance of the tuatara in their culture, which has never been done before in genomic research."Tuatara are a taonga, and it's pleasing to see the results of this study have now been published," Ng?tiwai Trust Board resource management unit manager Alyx Pivac said. "Our hope is that this is yet another piece of information that will help us understand tuatara and aid in the conservation of this special species. We want to extend a big mihi to all of those who have been involved in this important piece of work."With the genome now sequenced, the international science community has a blueprint through which to examine the many unique features of tuatara biology, which will aid human understanding of the evolution of the amniotes, a group that includes birds, reptiles and mammals.
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August 5, 2020
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https://www.sciencedaily.com/releases/2020/08/200805091834.htm
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Are vultures spreaders of microbes that put human health at risk?
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A new analysis published in
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The analysis examined results from published studies and found that microorganisms, which cause disease in humans, can be found in vultures with some bacterial pathogens showing multi-antibiotic resistance. In some cases, these microorganisms cause health alterations of variable degree in different vulture species, but there was no clear evidence that vultures play a role spreading pathogens to humans and other species. On the contrary, they may actually help to prevent the spread of infectious diseases when they consume and remove decomposing carcasses from the environment."Further research should evaluate the potential of vultures in disease regulation to avoid misconceptions and to promote scientific evidence of the ecosystem service they provide. This will help to conserve this globally threatened avian group and maintain the contributions they provide to people," said lead author Pablo Plaza, of INIBIOMA-CONICET-National University of Comahue, in Argentina.
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August 4, 2020
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https://www.sciencedaily.com/releases/2020/08/200804122218.htm
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Researchers develop new mouse model for SARS-CoV-2
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Researchers at Yale University School of Medicine have developed a new mouse model to study SARS-CoV-2 infection and disease and to accelerate testing of novel treatments and vaccines against the novel coronavirus. The study, published today in the
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Animal models that recapitulate SARS-CoV-2 infection and disease are urgently needed to help researchers understand the virus, develop therapies, and identify potential vaccine candidates. Mice are the most widely used laboratory animals, but they cannot be infected with SARS-CoV-2 because the virus is unable to employ the mouse version of ACE2, the cell surface receptor protein that the virus uses to enter human cells.SARS-CoV-2 can infect mice genetically engineered to produce the human version of ACE2. However, the availability of these animals is low and limited to a single mouse strain, preventing researchers from investigating how the virus impacts mice that are immunocompromised or obese, conditions that significantly increase the fatality rate in humans.In the new study, a team of researchers led by Akiko Iwasaki at Yale University School of Medicine developed an alternative mouse model of SARS-CoV-2 infection in which the animals are first infected with a different, harmless virus carrying the human ACE2 gene. Mice infected with this virus produce the human ACE2 protein and can then be infected with SARS-CoV-2. Iwasaki and colleagues found that SARS-CoV-2 can replicate in these mice and induce an inflammatory response similar to that observed in COVID-19 patients, where a wide variety of immune cells are activated and recruited to the lungs. "In addition, the infected mice also rapidly develop neutralizing antibodies against SARS-CoV-2," Iwasaki says.The body's response to viral infection often depends on signaling molecules called type I interferons that can activate immune cells and induce the production of antiviral proteins and antibodies. But too much type I interferon, especially when the production is delayed, can lead to excessive inflammation and tissue damage. Indeed, while type I interferon signaling protects against the related coronavirus MERS-CoV, it causes lung damage in response to SARS-CoV-1, the virus responsible for a previous coronavirus outbreak in 2002-2003.The role of type I interferons in COVID-19 is currently unclear. Iwasaki and colleagues found that, similar to COVID-19 patients, mice infected with SARS-CoV-2 activate a large number of genes associated with type I interferon signaling. The researchers then used their model system to infect mice lacking key components of the type I interferon pathway and found that they were no worse at controlling SARS-CoV-2 infection. However, these animals recruited fewer inflammatory immune cells into their lungs. "These results indicate that type I interferons do not restrict SARS-CoV-2 replication, but they may play a pathological role in COVID-19 respiratory inflammation," Iwasaki says. "This is especially concerning because type I interferons are currently being used as a treatment for COVID-19. The early timing of the IFN treatment will be important for it to provide protection and benefit."Iwasaki adds, "The mouse model we developed offers a broadly available and highly adaptable animal model to understand critical aspects of SARS-CoV-2 viral infection, replication, pathogenesis, and protection using authentic patient-derived virus. The model provides a vital platform for testing prophylactic and therapeutic strategies to combat COVID-19."
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August 4, 2020
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https://www.sciencedaily.com/releases/2020/08/200804093305.htm
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Dolphin calf entangled in fishing line only lived two years following rescue
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More than 1,000 bottlenose dolphins (
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Unfortunately, free-ranging common bottlenose dolphins can become entangled in fishing line and other marine debris. Reports of entanglement include a variety of items such as crab trap lines, human clothing, spearfishing gear, Frisbees, box strapping, and other objects. Infrequently, dolphins can be successfully disentangled and released back into the wild. It is rare, however, to encounter a case that can be followed from physically handling the dolphin at a disentanglement event to later recovering its carcass, enabling pathologic descriptions after an entanglement wound has healed.Researchers from Florida Atlantic University's Harbor Branch Oceanographic Institute and collaborators from Earth Resources Technology, Inc., the National Marine Mammal Foundation, and Georgia Aquarium Conservation Field Station, conducted a case study to examine the outcome of an entangled bottlenose dolphin calf found in the Indian River Lagoon with monofilament fishing line wrapped tightly around its maxilla or upper jaw. A multi-agency team successfully disentangled the dolphin and immediately released it back into its natural habitat.Because local bottlenose dolphin populations demonstrate site fidelity to the Indian River Lagoon, they are relatively easy to re-sight and monitor. The shallow, soft substrate in several inshore areas along the lagoon also allows for safe targeted capture and disentanglement efforts involving appropriately skilled biologists and veterinarians in cases where entanglements are deemed life threatening.For the study, published in the journal More than two years post-disentanglement, the freshly dead carcass of this juvenile dolphin was recovered with extensive predation wounds. Despite the forestomach being about 50 percent full of fish, the dolphin was emaciated. During postmortem examination, researchers collected and evaluated detailed photographs and measurements of the maxillary damage resulting from the entanglement."Entanglements in cetaceans such as dolphins can impede movement and impair foraging abilities, leading to starvation, systemic infections, and debilitation from severe tissue damage, pain and distress, and in some cases, death," said Annie Page-Karjian, D.V.M., Ph.D., assistant research professor and clinical veterinarian at FAU's Harbor Branch, who co-authored the paper with Wendy Marks, program coordinator, and Steve Burton, M.S., program director of stranding and population assessment, who are all members of the marine mammals stranding, health and rehabilitation project team.The monofilament entanglement caused permanent, bilateral deformation of the maxillary dental arcade, including a 4 to 4.2 centimeter long, 0.5 centimeter deep linear groove where the entanglement eroded the lateral edges of the maxilla. Entanglement in this 2-year-old dolphin did not cause bone fracture but did lead to bone deformity and maxillary malocclusion. External evidence of propeller scars and a fishing hook was discovered embedded in the laryngeal mucosa at necropsy, indicating repeated human interactions. The dolphin only survived for about two years after disentanglement and release."Educating fishermen about the importance of reeling in their lines when dolphins are present and proper disposal of fishing line can help reduce the risk of these interactions with bottlenose dolphins," said Page-Karjian. "Less lost fishing gear and fewer injured or dead marine wildlife benefits everyone. While the quick response to disentangle this dolphin may have initially saved its life, prevention of learned fishery interaction behaviors could have prolonged his life beyond the two plus years that were gained."This work was supported by Protect Wild Dolphins License Plate Funds, granted through the Harbor Branch Oceanographic Institute Foundation. The disentanglement intervention was funded by National Marine Fisheries Services (NOAA Fisheries) through a contract with the University Corporation for Atmospheric Research (UCAR).
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August 3, 2020
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https://www.sciencedaily.com/releases/2020/08/200803184154.htm
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Strong relationships in adulthood won't 'fix' effects of early childhood adversity
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Harsh conditions in early life are a fundamental cause of adult stress, and according to new research from the University of Notre Dame on wild baboons, this effect is not explained by a lack of social support in adulthood. The study is the first to present a comprehensive analysis of relationships between early life experiences, adult social bonds and adult stress responses within a single biological system.
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Published in the "Scientists have long believed that the link between early life adversity and adult stress could be due to a lack of social support in adulthood," said Elizabeth Archie, associate professor in the Department of Biological Sciences at Notre Dame and co-author of the study. "But what we've found through this study is that long-term effects of childhood hardships are more powerful than the near-term effects of social support -- even if those experiences took place many years in the past. The effects of early adversity and social support on stress appear to travel along independent physiological paths -- so 'fixing' one won't necessarily fix the other."One of the challenges to fully understanding how early childhood adversity can manifest in adulthood is that it requires measuring and tracking experiences from birth over the course of several decades.Archie's team analyzed data collected from 192 female baboons who were studied from birth through the Amboseli Baboon Research Project, an ongoing longitudinal effort that has been conducting research on the behavior of wild baboons in Kenya for almost 50 years. The animals are close evolutionary relatives to humans, and on average, they share a genetic similarity of 94 percent. Like many primates, baboons are highly social. They live in groups of around 20 to 150 animals, including several adult females, adult males and many offspring.For the study, researchers measured life experience against levels of glucocorticoids (fGCs) -- hormones that regulate physiological functions such as metabolism and immune function, and moderate the body's response to stress."Dysregulations in stress hormones or stress response are major risk factors for depression, anxiety, chronic inflammation and other health problems, so the experience of early life adversity is thought to contribute to global health disparities," said Archie, who also serves as associate director of the Amboseli project.Levels of fGCs in subjects who experienced three or more forms of childhood adversity were 9 percent higher than in those who experienced no hardships. Those who experienced two or more types of adversity showed fGC levels 14 percent higher than in peers who had endured only one form of hardship, and 21 percent higher than in peers who had experienced no hardship at all.While previous research has shown experiencing hardships in childhood can make it harder to form strong, supportive relationships as adults, the Notre Dame study found that even when social bonds were developed in adulthood, it had a minor effect on fGC levels and physiological responses to stress."Social bonds can have a significant effect on adult health, stress and survival," Archie said, "but they cannot make up for the effects of early life adversity -- which means targeting early life adversity itself is crucial for improving adult health."
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August 3, 2020
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https://www.sciencedaily.com/releases/2020/08/200803184149.htm
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Malignant cancer diagnosed in a dinosaur for the first time
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A collaboration led by the Royal Ontario Museum (ROM) and McMaster University has led to the discovery and diagnosis of an aggressive malignant bone cancer -- an osteosarcoma -- for the first time ever in a dinosaur. No malignant cancers (tumours that can spread throughout the body and have severe health implications) have ever been documented in dinosaurs previously. The paper was published August 3rd in the medical journal The
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The cancerous bone in question is the fibula (lower leg bone) from "Diagnosis of aggressive cancer like this in dinosaurs has been elusive and requires medical expertise and multiple levels of analysis to properly identify," says Crowther, who is also a Royal Patrons Circle donor and volunteer at the ROM. "Here, we show the unmistakable signature of advanced bone cancer in 76-million-year-old horned dinosaur -- the first of its kind. It's very exciting."After carefully examining, documenting, and casting the bone, the team performed high-resolution computed tomography (CT) scans. They then thin-sectioned the fossil bone and examined it under a microscope to assess it at the bone-cellular level. Powerful three-dimensional CT reconstruction tools were used to visualize the progression of the cancer through the bone. Using this rigorous process, the investigators reached a diagnosis of osteosarcoma.To confirm this diagnosis, they then compared the fossil to a normal fibula from a dinosaur of the same species, as well as to a human fibula with a confirmed case of osteosarcoma. The fossil specimen is from an adult dinosaur with an advanced stage of cancer that may have invaded other body systems. Yet it was found in a massive bonebed, suggesting it died as part of a large herd of "The shin bone shows aggressive cancer at an advanced stage. The cancer would have had crippling effects on the individual and made it very vulnerable to the formidable tyrannosaur predators of the time," says Evans, an expert on these horned dinosaurs. "The fact that this plant-eating dinosaur lived in a large, protective herd may have allowed it to survive longer than it normally would have with such a devastating disease."Osteosarcoma is a bone cancer that usually occurs in the second or third decade of life. It is an overgrowth of disorganized bone that spreads rapidly both through the bone in which it originates and to other organs, including most commonly, the lung. It is the same type of cancer that afflicted Canadian athlete Terry Fox and led to the partial amputation of his right leg prior to Fox's heroic Marathon of Hope in 1980."It is both fascinating and inspiring to see a similar multidisciplinary effort that we use in diagnosing and treating osteosarcoma in our patients leading to the first diagnosis of osteosarcoma in a dinosaur," says Seper Ekhtiari, an Orthopaedic Surgery Resident at McMaster University. "This discovery reminds us of the common biological links throughout the animal kingdom and reinforces the theory that osteosarcoma tends to affect bones when and where they are growing most rapidly."This study aims to establish a new standard for the diagnosis of unclear diseases in dinosaur fossils and opens the door to more precise and more certain diagnoses. Establishing links between human disease and the diseases of the past will help scientists to gain a better understanding of the evolution and genetics of various diseases. Evidence of many other diseases that we share with dinosaurs and other extinct animals may yet be sitting in museum collections in need of re-examination using modern analytical techniques.Funding for David Evans was provided by an NSERC Discovery Grant, and research computers for 3D visualization were generously supported by The Dorothy Strelsin Foundation.
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August 3, 2020
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https://www.sciencedaily.com/releases/2020/08/200803160457.htm
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Monkeying around: Study finds older primates father far fewer babies
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Infertility is a worldwide clinical problem for human health that affects 8 to 12 percent of couples. A new study from Washington University in St. Louis has implications for understanding some age-related aspects of male reproductive health in primates, including humans.
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Older male rhesus monkeys sire fewer offspring, even though they appear to be mating as much as younger monkeys with similarly high social status. Sperm quality or quantity, or the survival of infants, may decline with the age of the would-be father, the new study suggests.Researchers tracking a colony of free-ranging rhesus macaques in Puerto Rico reported their findings Aug. 3 in the journal "There have been a number of studies that explore female reproductive senescence in humans and other primates, but comparatively little work on male reproductive senescence," said Krista Milich, assistant professor of biological anthropology in Arts & Sciences."In fact, male reproductive success is thought to be primarily impacted by access to fertile females, but in this paper, we challenge that assumption."Cayo Santiago is a small primate research island in Puerto Rico. It is home to a colony of rhesus macaques that was established in 1938 with approximately 400 wild-caught animals from India. At the time of this study, more than 1,200 monkeys lived on the island.Researchers followed 21 adult males -- the highest ranking individuals in their social groups -- through breeding and birth seasons in a single year. All babies born that year were genotyped to determine both maternal and paternal lineage."We found that older, high-ranking males who were mating with females and who we would normally expect to produce a lot of offspring in a given mating season were actually producing very few or no offspring," Milich said."These are males that we know sired many offspring in their younger years, based on genetic records," she said. "We know from our behavioral data that they had access to mating partners at rates that were similar to or even higher than other males of similar social status."Yet, they were producing far fewer offspring than would be expected given their mating effort -- and fewer offspring than similarly ranked males that were younger."Their conclusion: Age brings fertility or mortality issues."These findings provide evidence of post-copulatory reproductive senescence -- in other words, the sperm quality or quantity or infant survival may decline with age [of the male]," Milich said.At Washington University, Milich leads the Reproductive Ecology and Behavioral Endocrinology Laboratory (REBEL). She and her research team members use ecological, behavioral, hormonal and genetic data to investigate certain long-held beliefs within the areas of sexual selection and sexual strategies.This new research can help fill a number of important gaps in understanding reproductive success in primates, Milich said.First, most research on aging and infertility in humans has focused on women.In addition, while some studies on age-related changes to men's sperm have been conducted, they provide contradictory evidence. And cross-cultural variations make the issues of aging and reproductive success difficult to understand through human studies.In other studies with different monkey species, declines in reproductive output for older males have been associated with a loss of dominance status, loss in attractiveness, and/or loss in body condition leading to a decline in mating activity.But the older rhesus monkeys in this study maintained high rates of mating behaviors while still experiencing the same decline in reproductive output."In populations where individuals are successfully mating and producing offspring, researchers should not use behavioral observations of mating patterns to determine paternity," Milich said. "As we saw in this study, those data do not necessarily match with the genetic paternity data."Future studies should continue to gather long-term data on variation in male reproductive health, and how social and physiological factors can impact a male's ability to sire offspring, said the study authors. Milich was joined by Angelina Ruiz-Lambides and Elizabeth Maldonado of the University of Puerto Rico plus Dario Maestripieri of the University of Chicago."Unfortunately, we have reached a level of deforestation and habitat destruction that impairs successful reproduction within some populations of wild animals," Milich said."In efforts to try to understand why certain populations have not been successful at producing any infants for years, sometimes even over a decade, researchers should take into consideration not only the age and stressors to females, but also the age of males," she said.
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August 3, 2020
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https://www.sciencedaily.com/releases/2020/08/200803120201.htm
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Oriole bird hybridization is a dead end
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A half-century of controversy over two popular bird species may have finally come to an end. In one corner: the Bullock's Oriole, found in the western half of North America. In the other corner: the Baltimore Oriole, breeding in the eastern half. Where their ranges meet in the Great Plains, the two mix freely and produce apparently healthy hybrid offspring. But according to scientists from the Cornell Lab of Ornithology, hybridization is a dead end and both parent species will remain separate. Findings from the new study were published today in
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"The debate over whether Bullock's and Baltimore Orioles are one species or two goes to the very heart of what defines a species," said lead author Jennifer Walsh, a postdoctoral researcher at the Cornell Lab. "For a long time, that definition included the inability of one species to reproduce with any other. Bullock's and Baltimore Orioles clearly can mate where their ranges overlap in the hybrid zone, but that's not the whole story."The oriole conundrum began with the birds long considered to be two distinct species. But the discovery that they interbreed caused the Bullock's and Baltimore Orioles to be lumped together under the name Northern Oriole in 1983, much to the consternation of birders and some biologists who felt that these birds were each highly distinct. In 1995, the American Ornithological Union reversed course and split them back into their two separate species. According to Cornell Lab researchers, this study may finally settle the lump-or-split debate.The researchers examined genetic markers from almost 300 orioles (Bullock's, Baltimore, and many hybrids) from the woodlands on the banks of the Platte River in Nebraska and Colorado. They found the oriole hybrid zone has been shrinking since it was first intensively studied in the 1950s. The scientists say if hybridization conferred any survival advantage, the zone would have gotten bigger, with more mixing of genes between the parent species, and more hybrids. Instead, ongoing natural selection pressures are limiting the expansion of the hybrid zone and preventing the homogenization of the two species."I call hybrid zones the 'supercolliders of speciation,'" says Irby Lovette, co-author and director of the Lab's Fuller Evolutionary Biology Program. "Through these special matings, genes and traits are mixing and matching in new combinations -- all of which helps us learn more about where biodiversity comes from, and therefore how new species arise."The orioles are not alone in their flexible mating standards -- about 10% of the world's bird species hybridize. Hybrid zones exist in the U.S. for Black-capped and Carolina Chickadees, Indigo and Lazuli Buntings, and others. But not all hybrid zones are following the same pattern as that of the orioles. For example, Blue-winged- and Golden-winged Warblers have hybridized so much they may be moving toward a merger of the two species."We're learning that hybrid zones are really very dynamic, shifting and changing over time," said study author Shawn Billerman. "That aspect of hybrid zones has become recognized as common and widespread in the past 10 to 20 years with the rapid improvement in genetic sequencing."Though the scientists feel the one-or-two species matter is probably settled, there are other questions they want to pursue. Their next steps are to identify the specific factors that are limiting oriole hybrid expansion, sequence the entire genome for both Bullock's and Baltimore Orioles, and determine the specific genes that cause differences in the appearance and behavior of the two orioles.
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Animals
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August 3, 2020
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https://www.sciencedaily.com/releases/2020/08/200803105230.htm
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Dingoes have gotten bigger over the last 80 years, and pesticides might be to blame
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Dingoes have gotten around 6-9 per cent bigger over the past 80 years, new research from UNSW and the University of Sydney shows -- but the growth is only happening in areas where poison baiting is used.
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The findings, published in the The scientists measured the skull size -- which is a marker of animal size -- of nearly 600 dingo specimens originating from the sites."Skulls from the baited regions grew by about four millimetres since poison baiting was introduced," says Michael Letnic, lead author of the paper and professor in conservation biology and ecosystem restoration at UNSW Science."This equates to roughly a kilogram in body mass."While both male and female dingoes grew, female dingoes had the biggest growth spurt: their skulls increased by 4.5 millimetres, which is almost 9 per cent body mass. Male skulls grew by 3.6 millimetres, or 6 per cent body mass.The question is: why are dingoes in poison-baited areas growing?"The most likely theory is that dingoes who survive baiting campaigns have less competition for food," says co-author Associate Professor Mathew Crowther from the University of Sydney.He explains that dingoes' primary prey, kangaroos, have been shown to increase in numbers when dingo populations are suppressed."With more food in abundance, dingoes' physical growth is less restricted."The pesticide sodium fluoroacetate -- known as 1080 (pronounced 'ten eighty') -- is commonly used across Australia to control dingo and other pest populations.A flavourless white powder, 1080 is usually stuck into meat baits and left in dingo hotspots, often via helicopter drops. Baiting was rolled out in Kalgoorlie, Pilbara and pastoral South Australia over the 1960s and 70s.Dingoes from the unbaited region -- which included Indigenous-owned lands and conservation reserves -- saw no change in body size.This is not the first time a pesticide has been linked to changes in animal bodies."Our interventions have consequences -- and they're actually quite predictable consequences," says Prof. Letnic."Whatever pressures we put on animal populations -- be it pesticides or not -- there will be side effects."Scientists usually observe these impacts in invertebrate pests: for example, some insects -- like cockroaches -- are becoming more resistant to the insecticides used on them.However, this study is one of the first to show that vertebrates, like dingoes, also change from pesticide use."Poison baiting campaigns could be favouring the survival of larger dingoes," says A/Prof. Crowther. "Smaller dingoes need less poison for a lethal dose, so are more likely to be killed by baiting. This leaves the larger dingoes to survive and breed."As a result of their growing size, the 1080 dose required to kill a dingo in the baited regions has increased since the toxin was introduced."The reaction to this finding may be to add more poison to the baits, or to find a new poison," says Prof. Letnic. "But, eventually, the cycle will start again."The exact mechanisms at play are still unclear -- but a greater abundance of food post-baiting and dingoes adapting to the poison are likely the most influential factors.Other factors that could have potentially led to the dingoes' growth, like climate change or interbreeding with dogs, seem unlikely."We only tested dingoes in areas that have very low dog hybridisation rates, making it highly unlikely that dog genetics are contributing to the size growth," says Prof. Letnic. Most dingo-dog hybridisation, he explains, occurs on the east coast of Australia.The researchers also suggest that -- if anything -- a warming climate would decrease dingoes' body size, as cooler conditions favour larger animals.Further studies that use a broader sample of dingoes from across Australia could help better understand the cause of the dingo body change.In the meantime, the researchers hope to explore other ecological impacts of 1080 baiting."Baiting is changing dingoes, so it could be changing other animal populations," says Prof. Letnic."Animals respond to human interventions, whether directly or indirectly. The changes could well be adaptive, and we must think about that."
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August 1, 2020
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https://www.sciencedaily.com/releases/2020/08/200801154158.htm
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New studies show how to save parasites and why it's important
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Parasites have a public relations problem.
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Unlike the many charismatic mammals, fishes and birds that receive our attention (and our conservation dollars), parasites are thought of as something to eradicate -- and certainly not something to protect.But only 4% of known parasites can infect humans, and the majority actually serve critical ecological roles, like regulating wildlife that might otherwise balloon in population size and become pests. Still, only about 10% of parasites have been identified and, as a result, they are mostly left out of conservation activities and research.An international group of scientists wants to change that. About a dozen leading parasite ecologists, including University of Washington's Chelsea Wood, published a paper Aug. 1 in the journal "Parasites are an incredibly diverse group of species, but as a society, we do not recognize this biological diversity as valuable," said Wood, an assistant professor in the UW School of Aquatic and Fishery Sciences. "The point of this paper is to emphasize that we are losing parasites and the functions they serve without even recognizing it."The authors propose 12 goals for the next decade that could advance parasite biodiversity conservation through a mix of research, advocacy and management."Even though we know little to nothing about most parasite species, we can still take action now to conserve parasite biodiversity," said Skylar Hopkins, paper and project co-lead and an assistant professor at North Carolina State University.Perhaps the most ambitious goal is to describe half of the world's parasites within the next 10 years. Providing taxonomic descriptions allow species to be named, which is an important part of the conservation process, the researchers said."If species don't have a name, we can't save them," said Colin Carlson, the other project co-lead and an assistant professor at Georgetown University. "We've accepted that for decades about most animals and plants, but scientists have only discovered a fraction of a percentage of all the parasites on the planet. Those are the last frontiers: the deep sea, deep space, and the world that's living inside every species on Earth."Importantly, the researchers stress that none of the parasites that infect humans or domesticated animals are included in their conservation plan. They say these parasites should be controlled to safeguard human and animal health.The paper is part of an entire special edition devoted to parasite conservation. Wood is the lead author on one study in the collection that finds the responses of parasites to environmental change are likely to be complex, and that a changing world probably will see both outbreaks of some parasites and a total loss of other parasite species."We need to recognize that there will be a diversity of responses among parasite taxa and not take for granted that every parasite is dwindling toward extinction or about to cause a major outbreak," Wood said.Parasites often need two or more host species to complete their lifecycle. For example, some parasites first infect fish or amphibians, but ultimately must get transmitted to birds to reproduce and multiply. They ensure that this happens through ingenious ways, Wood explained, often by manipulating the behavior or even the anatomy of their first host to make these fish or amphibians more susceptible to being eaten by birds. In this way, the parasite then gets transmitted to a bird -- its ultimate destination.Given this dynamic, Wood and colleagues wanted to see what would happen to the abundance of parasites if the ecosystems in which they live changed. They designed an experiment across 16 ponds in central California's East Bay region. In half of the ponds, they installed structures such as bird houses, floating perches and mallard decoys intended to attract more birds, thus temporarily altering the natural ecosystem and boosting biodiversity in these ponds.After a couple of years, the researchers analyzed parasite biodiversity in each of the 16 ponds. What they found was a mixed bag: Some parasite species responded to elevated bird biodiversity by declining in abundance. But other parasites actually increased in number when bird biodiversity increased. The authors concluded that as biodiversity changes -- due to climate change, development pressure or other reasons -- we can expect to see divergent responses by parasites, even those living within the same ecosystem.Traditionally, the field of disease ecology assumes one of two paths: That we are either heading toward a future of more disease and massive outbreaks or toward a future of parasite extinction. This paper shows that both trajectories are happening simultaneously, Wood explained."This particular experiment suggests that we need to anticipate both trajectories going forward. It starts to resolve the conflict in the literature by showing that everyone is right -- it's all happening," Wood said. "The trick now is to figure out what traits will predict which parasites will decline and which will increase in response to biodiversity loss."Wood's lab is working on that question now by reconstructing the history of parasites over time, documenting which parasites increased in abundance and which declined. However, there's almost no historical record of parasites and without this information, it's difficult to know how to conserve them. By dissecting museum specimens of fish, the researchers are identifying and counting various parasites found in the specimens at different places and times."These pickled animals are like parasite time capsules," Wood explained. "We can open them up and identify the parasites that infected a fish at its death. In this way, we can reconstruct and resurrect information that previously we didn't think was possible to get."
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