The mandrill is the world’s largest species of monkey weighing between 25-82 pounds, with female about 1/3 the size of the male.   He has adapted long canine teeth that can be used for self-defense but are usually presented as a sign of friendship among the other mandrills.  In excitement his teeth are exposed by curling back the lips, erecting the crest of the head and shaking it wildly.  Although it appears deadly when showing this display, he is usually just smiling and being cordial.  He also declares his identity to other animals in the forest and announces his virility to females through exaggerated gestures and scent marking while aggressively defending the territory against rivals.  Like squirrels, he has cheek pouches, which enable him to carry food to be stored and eaten later.  He efficiently walks and runs on all-fours, having fore-limbs and hind-limbs of nearly equal length and said to be among the most diverse genetic monkeys in the world. Often foraging in small parties , he grunts constantly to stay in touch with the others.  When it is time to move along, the dominant male will round up his group with very load grunts and roars.

Found on the continent of Africa in southern Camaroon, Gabon, Equatorial Guinea and the Congo, this brilliantly colored monkey prefers to live in tropical rainforests, savannah areas, rocky forests, agricultural areas and stream beds.  He is very good at spreading out and staying under cover and it can be difficult to find where he is living in the wild. Most of what has been learned about his species has been learned from those in captivity.  This  shy, elusive omnivore spends a majority of his time on the ground foraging for fruits, insects, amphibians and reptiles to feed on and then at night heads to the trees for peaceful sleep and as a safety precaution to get away from predators.  He has a very big appetite and will eat whatever he can find including plant matter, fruit, figs, leaves, tree bark, fibers roots and stems, ants, beetles, termites, crickets, spiders, scorpions, snails, birds, frogs, rodents, eggs and even the young of other species of monkeys. 

The mandrills lives in a large and stable group called a “horde” or “troop”, a lifestyle in which socialization plays a huge role.   Large groups with as many as 800 members have stayed together year after year, foraging for food, breeding, and fighting. A group having 1,350 individuals has even been recorded. These hordes have a very strict hierarchy with an alpha male, many females and young non-breeding males.  Some males live in harems with himself as the only male and up to 20 females. There have never been any reported all-male bachelor groups. Most male mandrills maintain solitary lifestyles and only enter hordes during mating season which lasts three months each year.  When not mating, the male tends to be a loner that may travel as much as 5 miles a day while feeding and sleeping in the trees at night. Adults have several partners, and females have single births. Young females stay with the group, but young males leave home at around age 4 or 5, fighting fiercely during mating season using their large, sharp canines. 

Breeding takes place every two years with the mating season being from June to October and births occurring from January to May, after a five month gestation period. Young are born with a black coat and pink skin.  At first the mother will carry her infant on her belly, but as it grows heavier, it will ride on her back while she travels through the forest. The female will initiate mating if she is interested in a desirable male.  The mothers are very excited to have the young arrive. They take very good care of them and won’t mate again until the young they have to care for are mature. If a baby should die then they will mate again in the hopes of being able to replace it.  Females provide most of the care for the young along with help from the babies’ siblings, aunts and cousins.  Males leave their groups when they reach maturity at five or six years old and only return during mating season. 

Natural predators of the mandrill are leopards, eagles, pythons, several other snake species, and human encroachment. The most immediate threat to them is posed by people hunting them for their meat, which is highly prized as a delicacy in Gabon and the Congo in Africa.   Commercial bushmeat hunters pose a great threat to mandrill populations close to towns and main roads.  In many areas the Mandrill is seen as a pest because they will destroy crops and living areas of the villagers. They have been hunted too because they aren’t afraid to come close to humans. 

This species is considered Vulnerable due to the the destruction of their evergreen forest habitat and the fact that they are constantly under siege and killed for their meat in many areas across Africa.  In some regions, the thriving bushmeat trade means the animals are being "eaten to extinction".   Nearly half of all primate species are now threatened with extinction, according to an evaluation by the International Union for the Conservation of Nature (IUCN). The study, which drew on the work of hundreds of scientists and is the most comprehensive analysis for more than a decade, found that the conservation outlook for monkeys, apes and other primates has dramatically worsened.