Vervet monkey
Vervet monkey[1] | |
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Adult male vervet monkey | |
Calls recorded at Lake Naivasha, Kenya | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Primates |
Suborder: | Haplorhini |
Infraorder: | Simiiformes |
Family: | Cercopithecidae |
Genus: | Chlorocebus |
Species: | C. pygerythrus
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Binomial name | |
Chlorocebus pygerythrus F. Cuvier, 1821
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Native range |
The vervet monkey (Chlorocebus pygerythrus), or simply vervet, is an
In addition to behavioral research on natural populations, vervet monkeys serve as a nonhuman primate model for understanding genetic and social behaviors of humans. They have been noted for having human-like characteristics, such as hypertension, anxiety, and social and dependent alcohol use.[4] Vervets live in social groups ranging from 10 to 70 individuals, with males moving to other groups at the time of sexual maturity. Studies done on vervet monkeys involve their communication and alarm calls, specifically in regard to kin and group recognition, and particular predator sightings.
Taxonomy
The vervet monkey was previously classified as Cercopithecus aethiops, now renamed '
Colin Groves recognised the below five subspecies of vervet monkey in the third edition of Mammals of the World:[1]
- Chlorocebus pygerythrus excubitor
- Ch. p. hilgerti from southern Kenya[7]
- Ch. p. nesiotes
- Ch. p. pygerythrus from South Africa, Botswana,[7] Lesotho, and Eswatini.[8]
- Ch. p. rufoviridis from Mozambique[7] and Uganda has a distinctly reddish-coloured back, which is darker towards the base of the tail.[9]
Groves used Ch. p. hilgerti for all East African vervets except the insular subspecies Ch. p. excubitor and Ch. p. nesiotes. The name Ch. p. centralis has been suggested to have precedence, and that Ch. p. hilgerti should be restricted to the population of southern Ethiopia.[10]
Synonymy
Ch. p. pygerythrus, as Cercopithecus aethiops, was also formerly divided into four subspecies:
- C. a. pygerythrus, from South Africa (Western Cape, Eastern Cape, Northern Cape and southern KwaZulu-Natal), and Lesotho; is said to have pale-colored limbs and white hands and feet (though the hands are also said to be black with a scattering of greyish hairs),[9] and a greyish body colour with an olive sheen.[8]
- C. a. cloetei, from northern KwaZulu-Natal, Eswatini, and northern South Africa; is darker, with greyish-brown speckles and dark feet.[8]
- C. a. marjoriae, from southern Botswana and the North West Province of South Africa; is pale in colour (light ash-grey).[8]
- C. a. ngamiensis,
These subspecies are no longer recognised and are synonymous with Ch. p. pygerythrus.
Distribution and habitat
Natural habitat
The vervet monkey ranges throughout much of Southern and East Africa, being found from Ethiopia and extreme southern South Sudan all the way down to South Africa. It is not found west of the East African Rift or the Luangwa River,[1] where it is replaced by the closely related malbrouck (C. cynosuros) species. The vervet monkey inhabits savanna, riverine woodland, coastal forest, and mountains up to 4000 m (13,100 ft). They are adaptable and able to persist in secondary and/or highly fragmented vegetation, including cultivated areas, and sometimes are found living in both rural and urban environments.[2] Annual home range size has been observed to be as high as 176 ha, with an average population density of 54.68 animals/km².
Introduced
Vervet monkeys that are naturalised (introduced by humans) are found in
Physical description
The vervet monkey very much resembles a
Behaviour
Social behaviour
When males reach sexual maturity, they move to a neighboring group.[18] Often, males move with a brother or peer, presumably for protection against aggression by males and females of the resident group. Groups that had previously transferred males show significantly less aggression upon the arrival of another male. In almost every case, males migrate to adjacent groups. This obviously increases benefits in regard to distance traveled, but also reduces the amount of genetic variance, increasing the likelihood of inbreeding.[19]
Females remain in their groups throughout life. Separate dominance hierarchies are found for each sex. Male hierarchies are determined by age, tenure in the group, fighting abilities, and allies, while female hierarchies are dependent on maternal social status. A large proportion of interactions occurs between individuals that are similarly ranked and closely related. Between unrelated individuals, female competition exists for grooming members of high-ranking families, presumably to gain more access to resources. These observations suggest individual recognition is possible and enables discrimination of genetic relatedness and social status. Interactions between different groups are variable, ranging from highly aggressive to friendly. Furthermore, individuals seem to be able to recognise cross-group vocalisations, and identify from and to which monkey each call is intended, even if the call is made by a subadult male, which is likely to transfer groups. This suggests the members within a group are actively monitoring the activity of other groups, including the movement of individuals within a group.[20]
Within groups, aggression is directed primarily at individuals that are lower on the hierarchy. Once an individual is three years or older, it is considerably more likely to be involved in conflict. Conflict often arises when one group member shows aggression toward a close relative of another. Further, both males and females may redirect aggression towards individuals in which both had close relatives that were previously involved in a conflict. This suggests complex recognition not only of individuals, but also of associations between individuals. This does not suggest recognition of other's individual kinship bonds is possible, but rather that discrimination of social relationships does occur.[21]
Alarm calls and offspring recognition
Vervet monkeys have four confirmed
Mothers can recognise their offspring by a scream alone. A juvenile scream elicits a reaction from all mothers, yet the juvenile's own mother has a shorter latency in looking in the direction of the scream, as well as an increased duration in her look. Further, mothers have been observed to help their offspring in conflict, yet rarely aid other juveniles. Other mothers evidently can determine to which mother the offspring belongs. Individuals have been observed to look towards the mother whose offspring is creating the scream.[25]
Kin relationships
Siblings likely provide the prevailing social relationships during development. Within social groups, mother-offspring and sibling interactive units are distinct groups. The sibling interactions are heavily supportive and friendly, but do have some competition. Contests primarily involve postweaning resource allocation by the common mother. For example, siblings have conflict over grooming time allocated by their mother. Offspring are usually not born in extremely close time proximity due to the interbirth period of the mother. This time can be reduced by use of an allomother. The clarity of the familial and sibships within a group may act as a form of alliance, which would come at relatively low cost in regards to grooming. Other alliances are shown through conflict with aggressive individuals that have acted against a closely related sibling.[26]
Allomothering is the process when another individual besides the mother cares for an infant. In groups of vervet monkeys, infants are the target of a tremendous amount of attention. Days after an infant is born, every member of the group inspects the infant at least once by touching or sniffing. While all group members participate in infant caretaking,
Grandmothers and grandchildren share one-quarter of their genes, so they should be more likely to form affiliative relationships than unrelated members in a group. Not only do infants approach their grandmothers more often than unrelated members, but they also prefer their grandmothers compared to other adult female kin, not including their own mothers. Additional research has shown grandmothers show no preference over the sex of their grandchild. Interest in the grandchild spurred from the rank of the grandmother within a group. Higher-ranking grandmothers showed more interest in caring for their grandchildren when compared to low-ranking grandmothers. The presence of grandmothers has been associated with a decrease in mortality of infants.[28]
Spite
Reproduction
Female vervets do not have external signs indicating
Ecology
Diet
The vervet monkey eats a primarily herbivorous diet, living mostly on wild fruits, flowers, leaves, seeds, and seed pods. In agricultural areas, vervets become problem animals, as they raid bean, pea, young tobacco, vegetable, fruit, and grain crops. Animal foods of their diet include
A list of some natural food plants and part of the plant eaten, in South Africa:[9][30]
- Acacia erioloba– seeds and pods
- Aloe spp – nectar (flowers)
- Celtis africana – fruit
- Colophospermum mopane– seeds
- Deinbollia oblongifolia – fruit
- Euphorbia ingens – fruit
- Euphorbia tirucalli – fruit
- Ficus abutilifolia – figs
- Ficus sur – figs
- Ficus sycomorus – figs
- Grewia caffra – fruit
- Harpephyllum caffrum– fruit
- Hyphaene coriacea – fruit
- Phoenix reclinata – fruit
- Protorhus longifolia – fruit
- Rhus chirindensis– fruit
- Sclerocarya birrea – fruit
- Strelitzia nicolai – soft parts of the flowers
- Ximenia caffra – fruit
- Ziziphus mucronata – fruit
Relationship with humans
The monkeys are used for biomedical research.[31] Many people living in close proximity to vervet colonies see them as pests, as they steal their food. Heavy fines in some areas discourage the killing of vervet monkeys.[32]
Its status according to the
This species was known in ancient
Gallery
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Adult male vervet monkey in South Africa
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Front view of the skull of a vervet monkey
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Side view of the skull
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Vervet monkeys in Samburu
References
- ^ OCLC 62265494.
- ^ . Retrieved 19 November 2021.
- ^ "Vervet Monkey (Chlorocebus pygerythrus)". iNaturalist. Retrieved 6 June 2023.
- PMID 9326311.
- ISBN 0-12-408355-2.
- ^ de Jong, Y.; Butynski, T. (14 January 2015). "A rainbow of savanna monkeys". National Geographic Society Newsroom. National Geographic. Retrieved 10 April 2021.
- ^ a b c Biodiversity occurrence data provided by: Field Museum of Natural History, Museum of Vertebrate Zoology, University of Washington Burke Museum, and University of Turku (Accessed through GBIF Data Portal, www.gbif.net, 2010-06-18)
- ^ ISBN 0-627-01686-3.
- ^ ISBN 0-86979-802-2.
- ISSN 0417-9927.
- ^ Meester, J. A. J., I. L. Rautenbach, N. J. Dippenaar, and C. M. Baker. 1986. Classification of southern African mammals. Transvaal Museum Monographs 5:1–359
- ISSN 0008-6495.
- ^ "Scientist concerned about vervet monkeys missing from Dania Beach colony". 11 February 2020.
- ^ Long, J. L. (2003). Introduced Mammals of the World: Their History, Distribution, and Influence. Csiro Publishing, Collingwood, Australia. ISBN 9780643099166
- ISBN 1-86825-757-6.
- ^ Fedigan, L.; Fedigan, L. M. (1988). Cercopithecus aethiops: a review of field studies. Cambridge (UK): Cambridge University Press. pp. 389–411.
- ^ Napier, P.H., ed. (1981). "Part II: Family Cercopithecidae, Subfamily Cercopithecinae". Catalogue of primates in the British Museum (Natural History) and elsewhere in the British Isles. London: British Museum (Natural History). p. 203.
- hdl:10500/8791.
- S2CID 84820877.
- JSTOR 3882575.
- S2CID 53165940.
- S2CID 53167785.
- ^ Estes, Richard Despard (2012). The behaviour guide to African mammals (20th Anniversary ed.). London England: University of California press.
- S2CID 53258798.
- S2CID 21449948.
- S2CID 53193890.
- S2CID 6784648.
- ^ Horrocks, J.; Hunte, W. (1981). "'Spite'; a constraint on optimal foraging in the vervet monkey Cercopithecus aethiops sabaeus in Barbados". American Zoology. 21: 939.
- ISBN 0-620-17697-0.
- ^ Foggo, D. (6 July 2008). "Germ warfare fear over African monkeys taken to Iran". The Times. London. Retrieved 27 March 2010.
- ^ Mngoma, N. (19 September 2014). "R10 000 reward for monkey killer". IOL. Retrieved 24 May 2017.
- .
- ^ Michael Hogan, C. (13 December 2007). "Akrotiri". Modern Antiquarian. Retrieved 13 July 2008.
- .
External links
- Vervet Monkey Foundation
- BBC story: Vervet monkeys raid farms
- Darwin Primate Group
- Vervet monkey, Primate Info Net
- Computerized atlas of vervet brain MRI
- Alcoholism in vervet monkeys