The Osman Hill's mangabey (''Lophocebus osmani''), also known as the rusty-mantled mangabey,
is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
crested mangabey
The crested mangabeys are West African Old World monkeys belonging to the genus ''Lophocebus''. They tend to have dark skin, eyelids that match their facial skin, and crests of hair on their heads. Another genus of mangabeys, ''Cercocebus'', was ...
in the family
Cercopithecidae
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 ...
with a restricted distribution in
West Africa
West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Maurit ...
.
Description
Osman Hill's mangabey is a medium-sized lanky, arboreal, dark furred monkey. The sexes are similar in colour and markings but males are far larger than females, the size difference being especially marked in this species compared to the other members of the grey-cheeked mangabey
superspecies. They have long, loose fur which is mainly blackish-brown, and a rufous tinged mane of longer hairs over the shoulders which is more noticeable in the males. The head shows a tuft on the crown and smaller tuft above the eyes, although these may not always be present, the cheeks are pale. The long tail is frequently held arched over the monkey's back. The two
ischial callosities
A callosity is another name for callus, a piece of skin that has become thickened as a result of repeated contact and friction.
Primates
All Old World monkeys, gibbons, and some chimpanzees have pads on their rears known as ischial callosities. ...
are bare and for a "C" shapes which are complete in the male but often broken in the females. The bare skin on such places as the palms and soles is pink in newborns but darkens as the get older and is normally black by nine months of age. A single male specimen has been measured and he had a head and body length of 610mm and a tail length of 920mm.
Distribution
Osman Hill's mangabey has a very small range from the
Cross River in south eastern
Nigeria
Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...
to the
Batouri district of south eastern
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 ...
.
[
]
Habitat
Osman Hill's mangabey occurs in low to medium altitude tropical rainforest where it is highly arboreal and can be seen in the canopy and emergent layers. It is rarely observed on the ground or in secondary or savanna habitats. The highest densities are found in swamp forest and flooded forest.[
]
Habits
This species and its close relatives have cheek pouches which they can use to store food to be eaten or processed later. The males have inflatable throat pouches which they use as resonators to amplify their loud low pitched calls which can be heard over a kilometre away from the calling male. They have powerful jaws, hands and arms which makes it possible for them to extract seeds from harder fruits, e.g. those of ''Monodora myristica
''Monodora myristica'', the calabash nutmeg, is a tropical tree of the family Annonaceae or custard apple family of flowering plants. It is native to Angola, Benin, Cameroon, the Central African Republic, the Democratic Republic of the Congo, Eq ...
'' than similarly sized monkeys. They are omnivorous, although fruit is the most important part of their diet, and they may locate fruiting trees by following the calls of frugivorous
A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...
birds such as hornbill
Hornbills (Bucerotidae) are a family (biology), family of bird found in tropical and subtropical Africa, Asia and Melanesia. They are characterized by a long, down-curved bill which is frequently brightly coloured and sometimes has a Casque (an ...
s. Important fruit tree species for Odsman Hill's mangabey include ''Erythrophleum suaveolens
''Erythrophleum suaveolens'', also known as the ordeal tree, is a species of flowering plant that can be found across most of tropical Africa. The species are in height, and have a rough and blackish bark. The plants leaves have 2–3 pairs of p ...
'' and ''Enantia chlorantha
''Enantia'' is a genus of butterflies in the subfamily Dismorphiinae. They are native to the Americas
The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South America. The ...
''. They also spend a lot of time splitting dead wood, excavating bark and searching through liana
A liana is a long- stemmed, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the canopy in search of direct sunlight. The word ''liana'' does not refer to a ta ...
tangles and epiphyte
An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...
masses searching for invertebrates.[
Osman Hill's mangabey is a social species living in groups of 10-20 individuals which consist of a few males, several females and their dependent young. These groups often associate with groups of other monkey species, and even occasionally with troops of ]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. Contact calls are grunts, alarm calls are staccato barks and the males make a loud "whoop gobble" to co-ordinate the group and to set spaces between different groups. This call can be made by females but very infrequently. The groups are fluid and will mix but this can lead to increased aggression among the adults, although the young will play. Females in oestrus
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 ...
may attract additional males. The dominant male usually guards receptive females but she will try and mate with other males when she can.[
]
Taxonomy
Osman Hill's mangabey used to be considered a 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 ...
of the grey-cheeked mangabey
The grey-cheeked mangabey (''Lophocebus albigena''), also known as the white-cheeked mangabey, is an Old World monkey found in the forests of Central Africa. It ranges from Cameroon down to Gabon. The grey-cheeked mangabey is a dark monkey, looki ...
, ''L. albigena''.[
]
Etymology
Osman Hill's mangabey was named after William Charles Osman Hill, a primatologist, anthropologist
An anthropologist is a person engaged in the practice of anthropology. Anthropology is the study of aspects of humans within past and present societies. Social anthropology, cultural anthropology and philosophical anthropology study the norms and ...
, and anatomist from the 20th century.
References
{{Taxonbar, from=Q1042209
Osman Hill's mangabey
The Osman Hill's mangabey (''Lophocebus osmani''), also known as the rusty-mantled mangabey, is a species of crested mangabey in the family Cercopithecidae with a restricted distribution in West Africa.
Description
Osman Hill's mangabey is a m ...
Mammals of Cameroon
Primates of Africa
Osman Hill's mangabey
The Osman Hill's mangabey (''Lophocebus osmani''), also known as the rusty-mantled mangabey, is a species of crested mangabey in the family Cercopithecidae with a restricted distribution in West Africa.
Description
Osman Hill's mangabey is a m ...
Taxobox binomials not recognized by IUCN
Taxa named by Colin Groves