the eastern gorilla ("gorilla beringei") is a critically endangered species of the genus "gorilla" and the largest living primate. the species is subdivided into two subspecies. grauer's gorilla, formerly known as the eastern lowland gorilla ("g. b. graueri") is more populous, at about 3,800. the mountain gorilla ("g. b. beringei") has only about 880. illegal hunting of these gorillas are the reason why they may go extinct.