Мандрилл: яркий примат Центральной Африки

Species of Old World monkey from Africathe primate

The mandrill (Mandrillus sphinx) is a large Old World monkey native to west central Africa. It is one of the most colorful mammals in the world, with red and blue skin on its face and posterior. The species is sexually dimorphic, as males have a larger body, longer canine teeth and brighter coloring. It is the largest monkey in the world. Its closest living relative is the drill, with which it shares the genus Mandrillus. Both species were traditionally thought to be baboons, but further evidence has shown that they are more closely related to white eyelid mangabeys. Mandrills mainly live in tropical rainforests but will also travel across savannas. They are active during the day and spend most of their time on the ground. Their preferred foods are fruit and seeds, but mandrills will consume leaves, piths, mushrooms, and animals from insects to juvenile bay duiker. Mandrills live in large, stable groups known as "hordes" which can number in the hundreds. Females form the core of these groups, while adult males are solitary and only reunite with the larger groups during the breeding season. Dominant males have the most vibrant colors and fattest flanks and rumps, and have the most success siring young. The mandrill is classified as vulnerable on the IUCN Red List. Its biggest threats are habitat destruction and hunting for bushmeat. Gabon is considered the stronghold for the species. Its habitat has declined in Cameroon and Equatorial Guinea, while its range in the Republic of the Congo is limited.

The word mandrill is derived from the English words man and drill—the latter meaning or and being West African in origin—and dated to 1744. The name appears to have originally referred to chimpanzees. The first scholar to record the name for the colorful monkey was Georges Louis Buffon in 1766. It was called the "tufted ape", "great baboon" and "ribbernosed baboon" by Thomas Pennant in A Synopsis of Quadrupeds (1771) and A History of Quadrupeds (1781).

The mandrill has a stocky body with a large head and muzzle, as well as a short and stumpy tail. The limbs are evenly sized and the fingers and toes are more elongated than those in baboons, with a more opposable big toe on the feet. The mandrill is the most sexually dimorphic primate, Most of the teeth are larger in males, and the canine teeth reach up to and long for males and females respectively. Both sexes have long tails. The red coloration is created by blood vessels near the surface of the skin, The blue ridges on males contrast with both the red facial hues and the green foliage of their environment, helping them stand out to other individuals. The darker and more subdued coloring of female faces is caused by melanin.

The mandrill lives in west central Africa, including southern Cameroon, mainland Equatorial Guinea (Río Muni), Gabon and parts of the Republic of the Congo. Its range is bounded by the Sanaga River to the north and the Ogooué and Ivindo Rivers to the east. It does not appear to share habitat with the drill, as the two species are separated by the Sanaga River. Mandrills live in tropical rainforests, generally preferring primary forests over secondary forests. They also live in patchy gallery forests surrounded by savanna and travel across grass areas within their forest habitats. They have also been recorded in mountainous areas, near rivers and in cultivated fields. Mandrills prefer thick bush dominated by perennial plants like gingers and plants of the genera Brillantaisia and Phaulopsis. During the wet season, mandrills forage in continuous forest, when fruit is most available, while during the dry season they feed in gallery forests and at the borders of savannas and forests. Adult male mandrills are one of the few primates capable of biting through the hard shell of Detarium microcarpum seeds.

Leopards may prey on mandrills, as traces of mandrill have been found in their feces. Other potential predators include African rock pythons, crowned eagles and chimpanzees. Mandrills can become infected with gastrointestinal parasites, such as nematodes and protozoa. Tumbu fly larvae may live under the skin and individuals that walk though grassland can get infested with ticks. Blood parasites include the malaria causing Plasmodium and the nematode Loa loa, which is transmitted by bites from deer flies. Wild mandrills have tested positive for SIV, enteroviruses of the species EV J and astroviruses, including a human variant.

Mandrills are mostly diurnal and are awake around 10 hours per day from morning to dusk. In the wild, mandrills appear to live 12–14 years, but captive individuals can live 30–40 years.

Mandrills live in large "supergroups" or "hordes" that can contain hundreds of individuals. Another study in Lopé found that a horde of 625 mandrills consisted of 21 dominant males, 71 less dominant and subadult males, 247 adult and adolescent females, 200 juveniles, and 86 dependent infants. A mandrill horde of around 700 individuals in northern Lopé had a total home range of , of which was suitable habitat. The supergroup would occasionally diverge into two to four subgroups before reuniting. Another 15 month long study of a 120 member group found a home range of with an average traveling distance of per day. Hordes consist of matrilineal family groups, and females are important for maintaining social cohesion. Strong connections with their relatives may lead to support during conflicts, higher survival rate of offspring and a longer lifespan for females. Dominant females are at the center of the group network and their removal leads to fewer social connections in the group. The social rank of a mother mandrill can contribute to the social rank of both her female and male offspring. Outside the breeding season, males are believed to lead a solitary life and all male bachelor groups are not known to exist. Mandrills will groom one another, even when there is no benefit to be gained from doing so. During grooming, subordinates prefer to pick at other mandrills from behind, in order to minimize eye contact and give them more time to flee if the more dominant individual attacks. The recipients of grooming will try to maneuver the groomer to pick at more "risky" areas.

Dominant or alpha male mandrills have the most mating success. Upon gaining alpha status, males develop larger testicles, redder faces and posteriors, more secretion from the chest glands and fatter sides and rumps. When a male loses dominance, these physiological changes are at least partially reversed. The blue facial skin is more consistent in brightness. Higher ranking males tend to have more contrast between red and blue facial coloring. Male mandrills tend to establish dominance with vocalizations and facial expressions, rather than fighting. Mating occurs mostly during the dry season, with female ovulation peaking between June and September. Receptive females have sexual swellings on their posteriors, and the red facial coloration can communicate age and fertility. Males also appear to detect a female's reproductive state using the vomeronasal organ (known as the flehmen response). Dominant males try to monopolize access to females by mate guarding, which involves the male tending to and copulating with a female for days. Dominant males tend to sire most of the offspring, but they are less able to monopolize access to the females when many females reach estrus at the same time. A subordinate male is also more likely to have reproductive success if he is closely related to an alpha male. An ovulating female tends to allow the brightest colored males to come near her and touch her perineum, and is more likely to groom and solicit them. The female signals her willingness to mate by positioning her posterior towards the male. Intercourse lasts no more than 60 seconds, with the male mounting the female and making pelvic thrusts. Mandrill gestation lasts an average of 175 days with most births taking place between January and March, during the wet season. Gaps in between births range from 184 to 1,159 days with an average of 405 days. and tend to be shorter in higher ranking females. Infants are born at an average weight of , and mostly bare skinned with some white hair and a tuft of dark hair on the head and along the spine. Over the next two or three months, they develop their adult hair color on the body, limbs and head while the flesh colored face and snout darken. Dependent infants are carried on their mothers' bellies.

Mandrills communicate with various facial expressions and postures. Threat displays involve open mouth staring, usually in combination with head bobbing, ground slapping and raised hair. These gestures are usually performed by dominant individuals towards subordinates, who respond with bared teeth grimaces, signaling fear and aggression. Both young and low ranking females show submission and anxiety with a pouting "duck face". Playful intentions are communicated with a relaxed open mouth face. Males approaching females display a "grin" or silent bared teeth face and make lip smacks. This display may also occur with teeth chattering. Mandrills can develop and pass on new gestures; captive individuals at the Colchester Zoo, England facepalm to discourage being disturbed, particularly while resting. Mandrills also produce several vocalizations, for both long and short distances. During group movements, adult males produce two phase grunts and one syllable roars, both of which are equivalent to the "wahoo" bark of baboons. Other group members produce "crowings", which last almost two seconds and start as a vibration and transition into a longer harmonic sound. Short distance vocals include the "yak", a sharp, repeating, pulse like call produced by all individuals except for adult males and made in tense situations. Mandrills may also grunt during aggressive encounters. Growls are used to express mild alarm while intense alarms come in the form of a short, two syllable sharp call known as the "k alarm". A sharp, loud "K sound" is produced for unknown reasons. Screaming is a signal of fear and made by individuals fleeing, while the girney, a type of moan or purr, is made as a form of appeasement or frustration among females and young. Individual voices are more similar among related animals, but unrelated mandrills can have similar voices if they regularly interact.

As of 2019, the IUCN Red List lists the mandrill as vulnerable. Its total population is unknown but is suspected to have decreased by more than 30 percent over the last 24 years. Its main threats are habitat destruction and hunting for bushmeat. There is at least one protected area for mandrills within each of the countries they inhabit. In Gabon, most of the rainforests have been leased to timber companies but around 10 percent is part of a national parks system, 13 of which were established in 2002.