Mandrills are the largest of the monkeys and are related to the baboon. Adult mandrill males are larger and more colorful than females. Their wariness of humans and their deep forest habitat makes them difficult research subjects, so they have never been fully studied in their native habitat.
Mandrills are primarily ground dwellers, only climbing into trees to sleep.
They walk on their toes and fingers, never letting the soles and palms touch the ground when walking. They will stand flat-footed. The mandrill range follows the moist evergreen rainforest of the countries of Cameroon, Congo, Equatorial Guinea, and Gabon in central West Africa. The coat is olive-brown to brownish black, with a dull white to gray underbelly. The male has a bright red, white, and blue face.