In the Masai Mara National Reserve in Kenya, Corinne Kendall works to learn more about some of East Africa's most threatened birds - the vultures. Vulture species are declining worldwide, with up to 99% declines in parts of central Asia. East Africa holds the world's most diverse guild of scavenging species. These African vultures play the crucially important role of removing dead animals and thus disease - acting as the "soap of the savannah".