sentence: topics include : hunting with golden eagle in the altai mountains of mongolia battling gelada monkeys in the semien mountains of ethiopia sulphur mining the ijen crater on the indonesian island of java catching giant bats in the new guinea highlands avalanche control in the swiss alps cataract surgery in the himalayas , nepal tibet sky burial behind the lens : hunting with golden eagles in the altai mountains episode 6 : grasslands -- roots of power first aired on thursday 17 february 2011 .