Mandrills are found in southwestern Cameroon, western Gabon, Equatorial Guinea, and southwestern Congo.
Mandrills are found in tropical rain forest habitats, montane and thick secondary forests, and thick bush. Although they are adapted to live in the ground, mandrills seek shelter in the trees during the night.
Mandrills reach a height of about 80 cm. The species is characterized by a large head, a compact body with long, powerful limbs, and a stubby tail, which is held upright. The wide rotating range of the clavicles enables climbing trees, the quadrupedal walk, and the functioning of the arms. Opposable thumbs allow these monkeys to grasp tree branches. Both sexes have paired mammary glands in the chest region.
The pelage is an olive green with paler underparts. It has a brilliantly colored blue to purple naked rump. A mandrill's face has a red stripe down the middle of the muzzle and aroung the nostrils, while the sides of the muzzle are ridged lengthwise and colored blue. This helps to distinguish this species from drills which have jet black faces. Mandrills have red fur patches above the eyes and a yellow beard. These colorings are duller in females and juveniles than in adult males.
These animals are reported to have average weights of 11.5 for females, and 25 kg for males. Males are significantly larger than females and may weigh up to 54 kg.
The head and body measurements range between 610 and 764 mm.
Mandrills live in groups, mostly in a harem structure, where a dominant male defends a group of females to whom he has exclusive mating rights.
Breeding is not seasonal but rather occurs about every two years, depending on the available food supply. Mating is believed to occur between July and October, while birthing occurs between December and April. Females give birth to their first young anywhere between 4 and 8 years of age. Gestation lasts for about 6 months after which females give birth to a single young. Twin young have only been observed in capivity. Infants are born with a black natal coat and pink skin, both of which endure for the first two months of life. (Macdonald, 1987)
Parental investment has not been extensively characterized in this species. However, it is likely that these animals are similar to other primates in which breeding occurs in a harem polygyny situation.
The bulk of the care for infants in such species is provided by the mother. Mothers give their young protection, grooming, and nourishment (milk). However, aunts, sisters, cousins, and other offspring of the mother may provide some care for young, including carrying, playing with, and grooming the young.
In species where one male mates with females, males also provide parental care. This may be direct, in the form of carrying, playing with, and grooming young, or it may be indirect, in that the father protects all the members of his harem group from potentially dangerous rival males.
The maximum lifespan reported for this genus is 46 years.
Mandrill groups can range in size from a few head up to 50 individuals. Although the dominant male often strays from the group, he will return immediately upon any sign of danger. Mandrills live on the ground by day and sleep in trees at night.
Their bright coloring is a key feature in social behavior. When excited, the blue color of the pad on their buttocks intensifies, their chest turns blue, and red dots may appear on the wrists and ankles. The flashing of the bright rump, which originated as a a signal of receptiveness in estruous females, has also been interpreted as an act of submissiveness in both sexes. This behavior, typical between subordinates and dominants, is considered "proper behavior."
To exhibit playfulness, a male mandrill shakes his head and shoulders; this is an invitation to be groomed. The exposure of teeth with the lips slightly lifted, accompanied by occasional chatter, is a sign of friendliness and general well-being.
When angered, mandrills slap the ground violently. They may stare intently at an observer while scratching their forearm or thigh.
A yawning gesture is given when mandrills are unable to carry out a desired activity, such as mating or fighting. This yawning also occurs as part of a threat where the mandrill spreads its arms, displays its lowered head, and flashes its powerful teeth.
Grooming is a common activity and may be accompanied by smacking noises similar to those heard during copulation. Mandrills communicate by grunting while in the forset; this maintains contact where visibility is low.
As described above in the section for behavior, communication is varied and complex in this species. It involves a variety of components, including visual and accoustic signals, scents, and tactile information.
Mandrills have a highly varied diet including fruit, seeds, fungi, roots, insects, snails, worms, frogs, lizards, and sometimes snakes and even small vertebrates. Generally, mandrill males scrounge for food on the ground while females and their young sit in midlevel trees.
Predators of this species have not been reported, but are likely to include large carnivores, such as leopards.
These monkeys are likely to play some role in seed dispersal. To the extent that they serve as predators or as prey, they may have some effect on local food webs.
Mandrills are commonly found in zoos. Becuse of their long life spans, they are valuable, longtime residents. The are also hunted for their meat in some areas.
In zoos, mandrills can be nuisances becuse they are very skillfull in taking articles from visitors, such as pipes and glasses. At the Zurich Zoo in Germany, glass had to be put up in front of the mandrill display for insurance reasons. In their natural habitat, mandrills may take oil palm fruits from local plantations. When food is scarce, they may also raid crops from nearby farms.
There has been a drastic decline in the mandrill population during recent years due to habitat destruction. They are especially vulnerable to hunters because of their loud calls. Mandrills are hunted as a local food source in several areas. Currently, mandrills occupy forests at a very low density and are poorly protectd if at all. As a result, they may be threatened with complete extinction in the wild. (Gale, 146)
Nancy Shefferly (editor), Animal Diversity Web.
Lisa Ingmarsson (author), University of Michigan-Ann Arbor.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
having more than one female as a mate at one time
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
associates with others of its species; forms social groups.
uses touch to communicate
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
breeding takes place throughout the year
Emanoil, M. (ed.). 1994. Encyclopedia of Endangered Species. Detroit: Gale Research, Inc.
Grzimek's Animal Life Encyclopedia. 1972. New York: Van Nostrand Reinhold Company.
Macdonald, David. 1987. Encyclopedia of Mammaks. Oxford: Equinox.
Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press.