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)
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: vulnerable
Predators of this species have not been reported, but are likely to include large carnivores, such as leopards.
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.
Range mass: 54 (high) kg.
Average mass: 11.5-25 kg.
Range length: 610 to 764 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger; male more colorful; ornamentation
The maximum lifespan reported for this genus is 46 years.
Average lifespan
Sex: female
Status: captivity: 31.7 years.
Average lifespan
Status: captivity: 46.0 years.
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.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
Mandrills are found in southwestern Cameroon, western Gabon, Equatorial Guinea, and southwestern Congo.
Biogeographic Regions: ethiopian (Native )
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.
Animal Foods: amphibians; reptiles; insects; mollusks; terrestrial worms
Plant Foods: roots and tubers; seeds, grains, and nuts; fruit
Other Foods: fungus
Primary Diet: omnivore
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.
Ecosystem Impact: disperses seeds
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.
Positive Impacts: food ; research and education
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.
Negative Impacts: crop pest
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.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
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.
Mating System: polygynous
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)
Breeding interval: Mandrills breed every two years.
Breeding season: Mating is believed to occur between July and October.
Average number of offspring: 1.
Average gestation period: 6 months.
Range age at sexual or reproductive maturity (female): 4 to 8 years.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 613 g.
Average gestation period: 173 days.
Average number of offspring: 1.
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.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Provisioning: Female, Protecting: Female); extended period of juvenile learning
Mandrills (Mandrillus sphinx) are the largest - and probably most conspicuous - of all monkeys. Male mandrills are far more colourful than females, and they use this colour as an advert of their virility as they try to win over the ladies. These social primates live in large, noisy troops headed up by a dominant male (‘drill sergeant?) who reigns over the lower ranking individuals. They are known to occur only in West Africa in Cameroon, Gabon, Equatorial Guinea and Congo.
Mandrill population are buckling under the strain of habitat loss as their natural forests give way to crops and villages. They are also targeted as bushmeat and consequently under IUCN species classifications they are considered ‘Vulnerable’.
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