N'etiti narị afọ nke 20 New York Zoological Society bụ instrumental na-emepe emepe echiche nke guzosie ike chebere maka akpan akpan umu na-eduzi na-eduzi ndị dị mkpa na-echekwa ọmụmụ iji chọpụta suitability nke ebe na-kasị kwesịrị ekwesị dị ka ichebe mkpa; ọrụ nke Henry Fairfield Osborn Jr., Carl E. Akeley, Archie Carr na nwa ya Archie Carr III bụ ịrịba ama n'oge a. Akeley ka ihe atụ, na-eduzi expeditions na Virunga Mountains na-ele ugwu gorilla na ọhịa, ghọrọ kwenyesiri ike na umu na ebe nile bụ nchebe mkpa.
Afọ 1990