Richard Despard Estes

This interest led Rod East, the former co-chair of the Antelope Specialist Group of the IUCN-World Conservation Union, to dub him the 'Guru of Gnu.

'[1] It has been suggested that Estes is responsible for most of the world's knowledge of wildebeest behaviour.

[2][3] Estes chose to study wildebeest because he thought they were 'the most interesting' animals he knew, particularly in their rutting behaviour.

He obtained his doctorate in the early 1960s with a thesis on the wildebeest of the Ngorongoro Crater, in which he advanced the theory that the females' estrus was triggered by the rumbling 'love call' of the males.

In 2004 he began a project in cooperation with the Smithsonian Institution to test his early theory using new advances in molecular chemistry.