These gentle baboons are one of the largest species of all the monkeys, and certainly one of the most colorful. Male mandrills, who weigh as much as 75 pounds, have bright red noses surrounded by blue ridges and purple grooves, and greenish- yellow fur. Female mandrills are much smaller, weighing up to 35 pounds, and lack the bright red nose and purple grooves of the male. Both male and female mandrills have bluish-lilac buttocks. The colors on the face and the buttocks deepen when the mandrill is excited or threatened.
Mandrills travel in large groups, led by one dominant adult male.
The male often travels at a distance from the group, but returns as soon as a danger to the group appears. He then threatens the enemy by lowering his impressive head, spreading his arms, and baring his teeth. Fruit, nuts, plants, and small animals are the preferred diet of mandrills. In their pouched cheeks they can store the equivalent of a stomach's worth of food. As a result of hunting and the destruction of their natural habitat, mandrills are endangered.