The Mandrill (Mandrillus sphinx) is a primate of the Cercopithecidae (Old-world monkeys) family, closely related to the baboons and even more closely to the Drill. Both the Mandrill and the Drill were once classified as baboons in genus Papio, but recent research has determined that they should be separated into their own genus, Mandrillus. The Mandrill is the world's largest species of monkey.

Description

The Mandrill is recognized by its olive-colored fur and the colorful face and rump of males, a coloration that grows stronger with sexual maturity; females have duller colours. This coloration becomes more pronounced as the monkey becomes excited and is likely to be an example of sexual selection. The coloration on the rump is thought to enhance visibility in the thick vegetation of the rainforest and aids in group movement.
Males average 25–30 kg (55-60 lb), females about half as much (11-14 kg, or 25-30 lb). Unusually large males can weigh 50 kg (110 lb).[2] The average male is 81 cm (32 in) and the female is 56 cm (22 in), with the tail adding another 5–8 cm (2–3 in).[3] They can survive up to 31 years in captivity. Females reach sexual maturity at about 3.5 years.

Habitat

The Mandrill is found in the tropical rainforests and occasionally woodlands of southern Cameroon, Gabon, Equatorial Guinea, and Congo. Its distribution is bounded by the Sanaga River to the north and the Ogooué and Ivindo rivers to the east. Recent research suggests that mandrill populations north and south of the Ogooué river are so genetically different as to be separate subspecies.

Behavior

Mandrills are social animals and live in large groups, primarily including females and young and led by a single dominant male. Most adult males are solitary. It is difficult to accurately estimate group size in the forest, but filming a group crossing a gap between two forest patches or crossing a road is a reliable way of estimating group size. The largest group verifiably observed in this way contained over 1300 individuals, in Lopé National Park, Gabon—the largest aggregation of non-human primates ever recorded [1].
The Mandrill is an omnivore and acquires its food by foraging (mainly plants, insects and smaller animals) from the ground as it is terrestrial. Although the Mandrill does not normally hunt larger prey, males have been observed to hunt and consume duiker (a small antelope).
Its main natural predators are leopards, pythons and humans. Attacks on subadults by African crowned eagles have also been reported. Mandrills are hunted for food throughout their range, either with guns or using dogs and nets. In Cameroon, habitat loss to agriculture is also a threat.
A large group of mandrills can cause significant damage to crops in a very short time, and where common they are widely perceived as pests.