![]() ![]() (Mandrillus)
![]() Colourful nose : The Mandrill (left) is the most colourful mammal and is more colourful than the drill (right). Both have colourful rear ends in hues from deep scarlet, reds and pinks to blue and a delicate lilac.
In the male drill, the face and muzzle are black, with red bands on the lower lip. Drills are dark brown with a black face, white tufted beard and scarlet lower lip.
The male mandrill goes one further and replicates his red and lilac genitals on his face. He has a bright red nose with bright blue bony ridges on either side. This mimics a snarl and the brightness and size of these ridges indicates the male's age and condition. The whole is framed with bright orange chin and side-whiskers. His colours brighten when he is excited: becoming bluer on his rump and chest, and red dots may appear on wrist and ankles! The female has smaller nose ridges and a grey-black face.
Why the colourful face? Males usually make up only 7% of the population, suggesting fierce competition among the males for breeding positions. In this competition, males gain advantage in prominently advertising his social position and readiness to mate. This may also explain why males are more than twice the size of females. Males also have larger canines. The males only colour up when they reach maturity.
![]() They move on all fours when foraging. They are active during the day, starting off at dawn. They may rest during the day in between foraging sprees. Although they forage on the ground, all climb trees for safety when threatened by predators, and sleep in trees at night.
![]() ![]() ![]() Mandrill talk: Drills are noisy, regularly grunting and screaming. Group members keep in contact with each other while foraging through loud conversations of grunting and crowing calls. They also alert each other of predators. A drill male's threat gesture is impressive including abruptly thrusting their head forwards, retracting their eyelids, puckering up their lips and raising the crest of fur on their heads. Both drill and mandrill males have chest glands which they regularly rub branches and tree trunks with. This scent helps to maintain the dominant male's aura.
Mating and babies: When the female is ready to mate, a marked swelling appears around her tail. The dominant male is the most likely to mate with her. Mandrill babies have a black coat and pink skin for the first 2 months.
Status and threats: CITES 1. Both drills and mandrills are better known in captivity than in the wild. There are about 3,000 left in the wild. The IUCN rated the drill as the highest priority among African primates. Drills are highly endangered because they are more localised, but mandrill populations have also suffered drastic declines. Both are severely hunted for their meat which is said to be sweet and is preferred over imported beef or mutton. Because they travel in large troops and are easily located by their constant grunting and screaming, entire populations are quickly decimated. Hunting has become lucrative and thus more efficient with the use of dogs, high-powered rifles, spotlights, deep-freezers and trucks. They are also killed as a pest on crops. In addition, they are severely affected by habitat loss due to logging and clearing for agriculture.
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VITAL STATISTICS
Size: Head and body 61-76cm, tail vestigial 5-7cm. Male average 25 kg, female 11.5kg. Mandrill males can reach 54 kg.
Lifespan: Average 20 years in the wild, 46 years in captivity.
Babies: One young, twins rare. Gestation 168-178 days, maturity at 4 years.
Social life: Harems of 1 male and 5-10 females. 6-7 harems may combine to form troops of up to 200.
Distribution: Africa. The Mandrill is more widely distributed in Western Central Africa: Cameroon, Gabon and the Congo. The drill is only found in Cameroon, north of the Sanaga River and on the coastal island of Fernando Poo.
Habitat: Prefer dense rainforests near rivers, but are occasionally seen in young secondary growths. They avoid open areas.
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