The endangered primate with the scientific name Mandrillus leucophaeus is the drill. It is an Old World monkey in the family Cercopithecidae and a close relative of the much better-known mandrill.
Drills live in fragmented forest populations in Nigeria, Cameroon, and Equatorial Guinea. They are among Africa’s largest monkeys and spend much of their time on the ground, although they can climb and forage in trees. Males are especially recognizable by their colorful facial and rump markings, while females and young animals are generally less vividly marked.
The drill and mandrill were once placed with baboons, but genetic and anatomical evidence supports their classification in the genus Mandrillus. The drill’s closest living relative is the mandrill, Mandrillus sphinx; the two species are separated geographically, notably around Cameroon’s Sanaga River.
Drills are threatened by hunting for the bushmeat trade, habitat loss, and fragmentation. The Bioko drill, a subspecies found on Bioko Island, is particularly affected by commercial hunting. A common quiz trap is choosing “mandrill” because of the similar genus name, but Mandrillus leucophaeus specifically identifies the drill.