The mandrill (''Mandrillus sphinx'') is a large
Old World monkey
Old World monkey is the common English name for a family of primates known taxonomically as the Cercopithecidae (). Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons ...
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
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
, as males have a larger body, longer canine teeth and brighter coloring. Its closest living relative is the
drill
A drill is a tool used for making round holes or driving fasteners. It is fitted with a bit, either a drill or driverchuck. Hand-operated types are dramatically decreasing in popularity and cordless battery-powered ones proliferating due to ...
with which it shares the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Mandrillus
''Mandrillus'' is a genus of large Old World monkeys distributed throughout central and southern Africa, consisting of two species: ''M. sphinx'' and ''M. leucophaeus'', the mandrill and drill, respectively. ''Mandrillus'', originally placed unde ...
''. Both species were traditionally thought to be
baboon
Baboons are primates comprising the genus ''Papio'', one of the 23 genera of Old World monkeys. There are six species of baboon: the hamadryas baboon, the Guinea baboon, the olive baboon, the yellow baboon, the Kinda baboon and the chacma ba ...
s, but further evidence has shown that they are more closely related to
white-eyelid mangabey
The white-eyelid mangabeys are African Old World monkeys belonging to the genus ''Cercocebus''. They are characterized by their bare upper eyelids, which are lighter than their facial skin colouring, and the uniformly coloured hairs of the fur. T ...
s.
Mandrills mainly live in
tropical rainforest
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatori ...
s but will also travel across
savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...
s. 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,
pith
Pith, or medulla, is a tissue in the stem
Stem or STEM may refer to:
Plant structures
* Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang
* Stipe (botany), a stalk to support some other ...
s, mushrooms, and animals from insects to juvenile
antelope
The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia.
Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mammals ...
. 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
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
. Its biggest threats are
habitat destruction
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
and hunting for
bushmeat
Bushmeat is meat from wildlife species that are hunted for human consumption, most often referring to the meat of game in Africa. Bushmeat represents
a primary source of animal protein and a cash-earning commodity for inhabitants of humid tropi ...
.
Gabon
Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...
is considered the stronghold for the species. Its habitat has declined in
Cameroon
Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the C ...
and
Equatorial Guinea
Equatorial Guinea ( es, Guinea Ecuatorial; french: Guinée équatoriale; pt, Guiné Equatorial), officially the Republic of Equatorial Guinea ( es, link=no, República de Guinea Ecuatorial, french: link=no, République de Guinée équatoria ...
, while its range in the
Republic of the Congo
The Republic of the Congo (french: République du Congo, ln, Republíki ya Kongó), also known as Congo-Brazzaville, the Congo Republic or simply either Congo or the Congo, is a country located in the western coast of Central Africa to the w ...
is limited.
Etymology
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
chimpanzee
The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative th ...
s. 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
Thomas Pennant (14 June Old Style, OS 172616 December 1798) was a Welsh natural history, naturalist, traveller, writer and antiquarian. He was born and lived his whole life at his family estate, Downing Hall near Whitford, Flintshire, in Wales ...
in ''A Synopsis of Quadrupeds'' (1771) and ''A History of Quadrupeds'' (1781).
Taxonomy
The mandrill was first scientifically depicted in ''
Historia animalium
''History of Animals'' ( grc-gre, Τῶν περὶ τὰ ζῷα ἱστοριῶν, ''Ton peri ta zoia historion'', "Inquiries on Animals"; la, Historia Animalium, "History of Animals") is one of the major texts on biology by the ancient Gr ...
'' (1551–1558) by
Conrad Gessner
Conrad Gessner (; la, Conradus Gesnerus 26 March 1516 – 13 December 1565) was a Swiss physician, naturalist, bibliographer, and philologist. Born into a poor family in Zürich, Switzerland, his father and teachers quickly realised his tale ...
, who considered it a kind of
hyena
Hyenas, or hyaenas (from Ancient Greek , ), are feliform carnivoran mammals of the family Hyaenidae . With only four extant species (each in its own genus), it is the fifth-smallest family in the Carnivora and one of the smallest in the clas ...
. The species was formally classified by
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
as ''Simia sphinx'' in 1758. Its current generic name ''
Mandrillus
''Mandrillus'' is a genus of large Old World monkeys distributed throughout central and southern Africa, consisting of two species: ''M. sphinx'' and ''M. leucophaeus'', the mandrill and drill, respectively. ''Mandrillus'', originally placed unde ...
'' was coined by
Ferdinand Ritgen in 1824.
Historically, some scientists placed the mandrill and the closely related
drill
A drill is a tool used for making round holes or driving fasteners. It is fitted with a bit, either a drill or driverchuck. Hand-operated types are dramatically decreasing in popularity and cordless battery-powered ones proliferating due to ...
(''M. leucophaeus'') in the baboon genus ''
Papio
Baboons are primates comprising the genus ''Papio'', one of the 23 genera of Old World monkeys. There are six species of baboon: the hamadryas baboon, the Guinea baboon, the olive baboon, the yellow baboon, the Kinda baboon and the chacma ba ...
''.
Morphological and
genetic studies
Genetic analysis is the overall process of studying and researching in fields of science that involve genetics and molecular biology. There are a number of applications that are developed from this research, and these are also considered parts of ...
in the late 20th and early 21st centuries found a closer relationship to
white-eyelid mangabey
The white-eyelid mangabeys are African Old World monkeys belonging to the genus ''Cercocebus''. They are characterized by their bare upper eyelids, which are lighter than their facial skin colouring, and the uniformly coloured hairs of the fur. T ...
s of the genus ''Cercocebus''. Some have even proposed that the mandrill and drill belong to ''Cercocebus''. Two genetic studies in 2011 clarified ''Mandrillus'' and ''Cercocebus'' as separate
sister lineages.
The two genera
split
Split(s) or The Split may refer to:
Places
* Split, Croatia, the largest coastal city in Croatia
* Split Island, Canada, an island in the Hudson Bay
* Split Island, Falkland Islands
* Split Island, Fiji, better known as Hạfliua
Arts, enterta ...
around 4.5 million years ago (mya) while the mandrill and drill split approximately 3.17 mya. Fossils of ''Mandrillus'' have not been found.
Some authorities have divided mandrill populations into
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
: the northern mandrill (''M. s. sphinx'') and the southern mandrill (''M. s. madarogaster''). A proposed third subspecies, ''M. s. insularis'', was based on the mistaken belief that mandrills are present on
Bioko Island
Bioko (; historically Fernando Po; bvb, Ëtulá Ëria) is an island off the west coast of Africa and the northernmost part of Equatorial Guinea. Its population was 335,048 at the 2015 census and it covers an area of . The island is located of ...
. The consensus is that mandrills belong to one subspecies (''M. s. sphinx'').
Cytochrome-b
Cytochrome b within both molecular and cell biology, is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes.
...
sequences suggest that mandrill populations north and south of the
Ogooué River
The Ogooué (or Ogowe), also known as the Nazareth river, some long, is the principal river of Gabon in west central Africa and the fifth largest river in Africa by volume of discharge, trailing only the Congo, Kasai, Niger and Zambezi. Its w ...
split 800,000 years ago and belong to distinct
haplogroup
A haplotype is a group of alleles in an organism that are inherited together from a single parent, and a haplogroup (haploid from the el, ἁπλοῦς, ''haploûs'', "onefold, simple" and en, group) is a group of similar haplotypes that share ...
s. This divergence appears to have also led to the splitting of the mandrill strain of the
simian immunodeficiency virus
''Simian immunodeficiency virus'' (''SIV'') is a species of retrovirus that cause persistent infections in at least 45 species of non-human primates. Based on analysis of strains found in four species of monkeys from Bioko Island, which was isola ...
(SIV).
The draft (incomplete)
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...
of the mandrill was published in 2020, with a reported
genome size
Genome size is the total amount of DNA contained within one copy of a single complete genome. It is typically measured in terms of mass in picograms (trillionths (10−12) of a gram, abbreviated pg) or less frequently in daltons, or as the total ...
of 2.90
giga–base-pairs and high levels of
heterozygosity
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism.
Mo ...
.
Appearance
![Mandrilperspective6](https://upload.wikimedia.org/wikipedia/commons/2/2d/Mandrilperspective6.jpg)
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
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
primate,
and the adult male is considered to be the largest
monkey
Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as the simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes, which constitutes an incomple ...
. Females are less stocky and have shorter, flatter snouts. Males have a head-body length and weigh while females have a head-body length and weigh .
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 ]coat
A coat typically is an outer garment for the upper body as worn by either gender for warmth or fashion. Coats typically have long sleeves and are open down the front and closing by means of buttons, zippers, hook-and-loop fasteners, toggles, a ...
of the mandrill is primarily grizzled or banded olive-brown with a yellow-orange beard and sparse, light hairs on its underside.[ The lips are surrounded by stiff white ]whiskers
Vibrissae (; singular: vibrissa; ), more generally called Whiskers, are a type of stiff, functional hair used by mammals to touch, sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are c ...
, and white bare skin exists behind the ears. Male mandrills have a "crest" of long hairs on the head and neck, while both sexes have chest glands which are covered by long hairs. The face, rump and genitals have less hair.
Mandrills have a red line running down the middle of their face which connects to their red nose. On either side of the line, the skin is blue and grooved.[ In males, the blue skin is supported by ridged bone swellings. Females have more subdued facial coloring, but this can vary between individuals with some having stronger red and blue hues and others being darker or almost black. In males, the rump and areas around the genitals are multi-colored, consisting of red, pink, blue and purple skin,] with a red penis shaft and violet scrotum. The genital and anal areas of the female are red.
Mandrills are noted for being among the most colorful mammals. Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended fr ...
wrote in ''The Descent of Man
''The Descent of Man, and Selection in Relation to Sex'' is a book by English naturalist Charles Darwin, first published in 1871, which applies evolutionary theory to human evolution, and details his theory of sexual selection, a form of biolo ...
'': "no other member of the whole class of mammals is coloured in so extraordinary a manner as the adult male mandrill". The red coloration is created by blood vessels near the surface of the skin, while the blue is a form of structural coloration
Structural coloration in animals, and a few plants, is the production of colour by microscopically structured surfaces fine enough to interfere with visible light instead of pigments, although some structural coloration occurs in combination wit ...
caused by parallel arrangements of collagen
Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole ...
fibers. 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
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...
.
Ecology
The mandrill lives in west-central Africa, including southern Cameroon
Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the C ...
, mainland Equatorial Guinea
Equatorial Guinea ( es, Guinea Ecuatorial; french: Guinée équatoriale; pt, Guiné Equatorial), officially the Republic of Equatorial Guinea ( es, link=no, República de Guinea Ecuatorial, french: link=no, République de Guinée équatoria ...
(Río Muni
Río Muni (called ''Mbini'' in Fang) is the Continental Region (called ''Región Continental'' in Spanish) of Equatorial Guinea, and comprises the mainland geographical region, covering . The name is derived from the Muni River, along which ...
), Gabon
Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...
and parts of the Republic of the Congo
The Republic of the Congo (french: République du Congo, ln, Republíki ya Kongó), also known as Congo-Brazzaville, the Congo Republic or simply either Congo or the Congo, is a country located in the western coast of Central Africa to the w ...
. Its range is bounded by the Sanaga River
The Sanaga River (formerly german: Zannaga) is the largest river in Cameroon located in East Region, Centre Region and Littoral Region. Its length is about from the confluence of Djérem and Lom River. The total length of Sanaga-Djérem Rive ...
to the north and the Ogooué and Ivindo River
The Ivindo River is the most important tributary of the Ogooué River, which flows in Gabon.
Course
The Ivindo River flows from northeast Gabon to the southwest, eventually emptying into the Ogooué River. It flows through some of the wildest an ...
s 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 rainforest
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatori ...
s, generally preferring primary forest
An old-growth forestalso termed primary forest, virgin forest, late seral forest, primeval forest, or first-growth forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological featur ...
s over secondary forest
A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. ...
s. They also live in patchy gallery forest
A gallery forest is one formed as a corridor along rivers or wetlands, projecting into landscapes that are otherwise only sparsely treed such as savannas, grasslands, or deserts. The gallery forest maintains a more temperate microclimate above th ...
s surrounded by savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...
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 plant
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
s like ginger
Ginger (''Zingiber officinale'') is a flowering plant whose rhizome, ginger root or ginger, is widely used as a spice
A spice is a seed, fruit, root, bark, or other plant substance primarily used for flavoring or coloring food. Spices ...
s and plants of the genera ''Brillantaisia
''Brillantaisia'' is a genus of plants in the family Acanthaceae. They are native to the African tropics and subtropics, including Madagascar. They may grow from 20 cm to 2 m in height. Their hirsute stems are square in cross-section and the ...
'' and '' Phaulopsis''. They mainly dwell on the ground, but feed as high as the canopy
Canopy may refer to:
Plants
* Canopy (biology), aboveground portion of plant community or crop (including forests)
* Canopy (grape), aboveground portion of grapes
Religion and ceremonies
* Baldachin or canopy of state, typically placed over an a ...
. Both mandrills and drills are more arboreal
Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...
than baboons. Mandrills may aggregate or compete with other primates such as talapoin
__NOTOC__
Talapoins () are the two species of Old World monkeys classified in genus ''Miopithecus''. They live in central Africa, with their range extending from Cameroon and the Democratic Republic of the Congo to Angola.
With a typical length o ...
s, guenon
The guenons (, ) are Old World monkeys of the genus ''Cercopithecus'' (). Not all members of this genus have the word "guenon" in their common names; also, because of changes in scientific classification, some monkeys in other genera may have co ...
s, mangabeys, black-and-white colobus
Black-and-white colobuses (or colobi) are Old World monkeys of the genus ''Colobus'', native to Africa. They are closely related to the red colobus monkeys of genus '' Piliocolobus''. There are five species of this monkey, and at least eight subs ...
es, chimpanzees and gorilla
Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or fi ...
s.
Feeding
The mandrill is an omnivore
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutr ...
. The core of its diet consists of plants, of which it eats over a hundred species. One study found the mandrill's diet was composed of fruit (50.7%), seeds (26.0%), leaves (8.2%), pith
Pith, or medulla, is a tissue in the stem
Stem or STEM may refer to:
Plant structures
* Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang
* Stipe (botany), a stalk to support some other ...
(6.8%), flowers (2.7%), and animal matter (4.1%), with other foods making up the remaining 1.4%. 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.
The mandrill's preferred fruits include those of the cashew
The cashew tree (''Anacardium occidentale'') is a tropical evergreen tree native to South America in the genus ''Anacardium'' that produces the cashew seed and the cashew apple accessory fruit. The tree can grow as tall as , but the dwarf cult ...
species '' Pseudospondias microcarpa'', the coffee
Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulant, stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world.
S ...
species ''Nauclea diderrichii
''Nauclea diderrichii'' is a species of tree of the genus ''Nauclea'' in the family Rubiaceae. It is known by the common names bilinga, aloma, badi, and .
Description
''Nauclea diderrichii'' is found in Angola, Cameroon, Central African Republ ...
'' and the wort
Wort () is the liquid extracted from the mashing process during the brewing of beer or whisky. Wort contains the sugars, the most important being maltose and maltotriose, that will be fermented by the brewing yeast to produce alcohol. Wort ...
species ''Psorospermum febrifugum
''Psorospermum febrifugum'' is a flowering plant species in the genus ''Psorospermum'' occurring in Africa. It grows in open woodland over a wide range of altitudes. The inconspicuous flowers are fragrant, creamy-white and some 8mm in diameter. T ...
''. Mandrills consume more seeds than many other primate species. Adult male mandrills are one of the few primates capable of biting through the hard shell of ''Detarium microcarpum
''Detarium microcarpum'' ( bm, Ntamajalan), commonly known as sweet detar, sweet dattock or tallow tree, is an underutilized species of tree legume that grows naturally in the drier regions of West and Central Africa. It has a wide range of uses ...
'' seeds. For vegetation, they mostly eat the young leaves, shoots and piths of monocot
Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of ...
plants. In particular, mandrills consume leaves from the arrowroots '' Haumania liebrechtsiana'' and '' Trachyphrynium braunianum'', as well as the piths of ginger plants like '' Renealmia macrocolia'' and species in the genus ''Aframomum
''Aframomum'' is a genus in the ginger family, Zingiberaceae. It is widespread across tropical Africa as well as on some islands of the Indian Ocean (Madagascar, Seychelles, and Mauritius). It is represented by approximately 50 species. It i ...
''. They are also known to consume mushrooms.
The rest of a mandrill's diet is largely made up of invertebrates, particularly ant
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...
s, termite
Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...
s, cricket
Cricket is a bat-and-ball game played between two teams of eleven players on a field at the centre of which is a pitch with a wicket at each end, each comprising two bails balanced on three stumps. The batting side scores runs by striki ...
s, spider
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...
s, snail
A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastro ...
s, and scorpion
Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always end ...
s. They also eat birds and their eggs, frogs and rodents. Mandrills have been recorded preying on larger vertebrates such as juvenile bay duiker
The bay duiker (''Cephalophus dorsalis''), also known as the black-striped duiker and the black-backed duiker, is a forest-dwelling duiker native to western and southern Africa. It was first described by British zoologist John Edward Gray in 18 ...
s. Such prey is killed with a bite to the head followed by pulling off the hind limbs and tearing open the belly. Individuals may cooperate during hunting and share kills.
Predators, parasites and pathogens
Leopard
The leopard (''Panthera pardus'') is one of the five extant species in the genus '' Panthera'', a member of the cat family, Felidae. It occurs in a wide range in sub-Saharan Africa, in some parts of Western and Central Asia, Southern Russia, a ...
s may prey on mandrills, as traces of mandrill have been found in their feces. Other potential predators include African rock python
The Central African rock python (''Python sebae'') is a species of large constrictor snake in the family Pythonidae. The species is native to sub-Saharan Africa. It is one of 11 living species in the genus ''Python''.
Africa's largest snake and ...
s, crowned eagle
The crowned eagle, also known as the African crowned eagle or the crowned hawk-eagle (''Stephanoaetus coronatus''), is a large bird of prey found in sub-Saharan Africa; in Southern Africa it is restricted to eastern areas.Sinclair & Ryan (2003) ...
s and chimpanzees. Leopards are a threat to all individuals, while eagles are only threats to the young. In a study where a mandrill group was exposed to models of leopards and crown eagles, the leopard models tended to cause the mandrills to flee up trees while the eagles were more likely to drive them to take cover. The dominant male did not flee from either model types; in the case of the leopards, he paced around while looking in their direction. Alarm call
In animal communication, an alarm signal is an antipredator adaptation in the form of signals emitted by social animals in response to danger. Many primates and birds have elaborate alarm calls for warning conspecifics of approaching predators ...
s were more commonly heard in response to leopards than eagles.
Mandrills can become infected with gastrointestinal parasites, such as nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
s and protozoa
Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...
. Tumbu fly larvae may live under the skin and individuals that walk though grassland can get infested with tick
Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...
s. Blood parasites include the malaria
Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...
-causing ''Plasmodium
''Plasmodium'' is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of ''Plasmodium'' species involve development in a blood-feeding insect host which then injects parasites into a vert ...
'' and the nematode ''Loa loa
''Loa loa'' is a filarial (arthropod-borne) nematode (roundworm) that causes ''Loa loa'' filariasis. ''Loa loa'' actually means "worm worm", but is commonly known as the "eye worm", as it localizes to the conjunctiva of the eye. ''Loa loa'' is ...
'', which is transmitted by bites from deer flies
Deer flies (also known in some parts of the mid-Atlantic United States as sheep flies) are bloodsucking insects considered pests to humans and cattle. They are large flies with large brightly-coloured compound eyes, and large clear wings with da ...
. Wild mandrills have tested positive for SIV, enterovirus
''Enterovirus'' is a genus of positive-sense single-stranded RNA virus
An RNA virus is a virusother than a retrovirusthat has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA ( ssRNA) but it ma ...
es of the species EV-J and astrovirus
Astroviruses are a type of virus that was first discovered in 1975 using electron microscopes following an outbreak of diarrhea in humans. In addition to humans, astroviruses have now been isolated from numerous mammalian animal species (and are ...
es, including a human variant.[
]
Behavior and life history
Mandrills are mostly diurnal and are awake around 10 hours per day from morning to dusk.[ They often pick a new tree to sleep in every night.] Mandrills have been observed using tools; in captivity, they use sticks to clean themselves. In the wild, mandrills appear to live 12–14 years, but captive individuals can live 30–40 years.
Social structure
Mandrills live in large "supergroups" or "hordes" that can contain hundreds of individuals. These large groups are fairly stable and do not appear to be gatherings of smaller ones. At Lopé National Park
Lopé National Park is a national park in central Gabon. Bordered by the Ogooué River to the north and the Chaillu Massif to the south, the park takes up roughly 4912 square kilometers. Although the terrain is mostly monsoon forest, in the nor ...
, Gabon, mandrill hordes were found to have an average of 620 individuals, and some groups were as large as 845, making them possibly the largest cohesive groups of wild primates. 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
A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He ...
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
Matrilineality is the tracing of kinship through the female line. It may also correlate with a social system in which each person is identified with their matriline – their mother's Lineage (anthropology), lineage – and which can in ...
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.[ Mature males are not permanent members of hordes but join as females become sexually receptive and leave as their sexual cycle ends. As a result, the coloration of the male mandrill may be intended to attract attention in a social structure with no long-term relationships between mates.] Higher ranking males are found in the center of a social group while lower ranking males are more likely to occupy the periphery.[ Females have some control over the males and coalitions can expel an unwanted male from a group. Outside the breeding season, males are believed to lead a solitary life and all-male bachelor groups are not known to exist.]
Both male and female mandrills rub and mark trees and branches with secretions from their chest glands, though males (and especially dominant males) mark more than females. The chemicals in the secretions signal the individual's sex, age and rank. Scent-marking may also serve a territorial
A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal.
In international politics, a territory is usually either the total area from which a state may extract power resources or a ...
function, captive alpha males will mark enclosure boundaries. Mandrills will groom
A bridegroom (often shortened to groom) is a man who is about to be married or who is newlywed.
When marrying, the bridegroom's future spouse (if female) is usually referred to as the bride. A bridegroom is typically attended by a best man an ...
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.
Reproduction and development
Dominant or alpha male
In biology, a dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social groups interact, creating a ranking system. A dominant higher-ranking individual is som ...
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. Due to their distribution of fat, dominant males are also known as "fatted" males while subordinate males are known as "non-fatted" males. Canine length also correlates with dominance, and males are less likely to sire offspring when their canines are under . Some individuals suppress the development of secondary sexual characteristic
Secondary sex characteristics are features that appear during puberty in humans, and at sexual maturity in other animals. These characteristics are particularly evident in the sexual dimorphism, sexually dimorphic phenotypic traits that distinguis ...
s in response to competition from other males. Male mandrills prefer to establish dominance with vocalizations and facial expressions since fighting is dangerous due to the long canines.
Mating occurs mostly during the dry season, with female ovulation
Ovulation is the release of eggs from the ovaries. In women, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilized ...
peaking between June and September. Receptive females have sexual swelling
Sexual swellings are enlarged areas of genital and perineal skin occurring in some female primates that vary in size over the course of the menstrual cycle. Thought to be an honest signal of fertility, male primates are attracted to these swell ...
s 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
The vomeronasal organ (VNO), or Jacobson's organ, is the paired auxiliary olfactory (smell) sense organ located in the soft tissue of the nasal septum, in the nasal cavity just above the roof of the mouth (the hard palate) in various tetrapods. ...
(known as the flehmen response
The flehmen response (; from German ''flehmen'', to bare the upper teeth, and Upper Saxon German ''flemmen'', to look spiteful), also called the flehmen position, flehmen reaction, flehmen grimace, flehming, or flehmening, is a behavior in whic ...
). 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
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
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
The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includi ...
, 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. Young are typically weaned at around 230 days old. Males become more sexually dimorphic between four and eight years old, at which point females are already beginning to give birth.[ Males start leaving their horde after they reach six years old.] Females reach their adult size around seven years while males do so at ten years.
Communication
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
Colchester Zoo is a zoological garden situated near Colchester, England. The zoo opened in 1963 and celebrated its 50th anniversary on 2 June 2013. It is home to many rare and endangered species, including big cats, primates and birds as well as ...
, England facepalm
A facepalm is the physical gesture of placing one's hand across one's face, lowering one's face into one's hand or hands or covering or closing one's eyes. The gesture is often exaggerated by giving the motion more force and making a slapping noi ...
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.
Threats and conservation
As of 2019, the IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
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
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
and hunting for bushmeat
Bushmeat is meat from wildlife species that are hunted for human consumption, most often referring to the meat of game in Africa. Bushmeat represents
a primary source of animal protein and a cash-earning commodity for inhabitants of humid tropi ...
.[ The mandrill appears to have suffered massive habitat loss in Equatorial Guinea and southern Cameroon, while its range in the Republic of the Congo is limited and its status is unknown. In addition, while mandrills live in groups numbering in the hundreds, hunting in Cameroon and Equatorial Guinea appears to have led to smaller group sizes.][ Gabon is seen as the most important remaining refuge for the species, and the country's low population density and vast rainforests make it a good candidate for mandrill conservation. Surveys have shown high population numbers for other primate species like chimpanzees and gorillas. A semi-wild population exists at the International Centre of Medical Research of Franceville.
The mandrill is listed under Appendix I by ]CITES
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
, banning commercial trade in wild-caught specimens, and under Class B by the African Convention
African Convention (french: Convention Africaine, CA) was a political party in French West Africa, originally formed at a meeting in Dakar on 11 January 1957. The CA consisted of the Senegalese Popular Bloc (BPS) of Léopold Sédar Senghor, the Afr ...
, which provides them protection but allows special authorization for their killing, capturing or collecting. There is at least one protected area
Protected areas or conservation areas are locations which receive protection because of their recognized natural, ecological or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the ena ...
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.
]
References
Works cited
*
External links
* ARKive
images and movies of the mandrill ''(Mandrillus sphinx)''
Mandrillus Porject
– a research and conservation organization
{{Taxonbar, from=Q189868
Articles containing video clips
Fauna of Central Africa
Mammals described in 1758
Mammals of Cameroon
Mammals of Equatorial Guinea
Mammals of Gabon
Mammals of the Republic of the Congo
Mandrillus
Primates of Africa
Taxa named by Carl Linnaeus
Tool-using mammals
Vulnerable animals
Vulnerable biota of Africa