Chlorocebus aethiopsvervet monkey(Also: green monkey; grivet)

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Geographic Range

Vervet monkeys (Chlorocebus aethiops) are found from Senegal to Ethiopia and south to South Africa. These monkeys are found in northeast Africa from the Red Sea near Tokar, south through Abyssinia as far as 5 degrees north, and west to the eastern range of the Tantalus. (Hill,1965)

Habitat

Bush steppe country in tablelands of the Southern Sudan and Abyssinia. Vervets must drink water daily in the dry seasons, and therefore their habitat is limited to those near constant water supplies. (Hill, 1965)

Physical Description

Chlorocebus aethiops is usually around 400 to 600 mm in length (head and body), with tales about 300 to 500 mm. weights typically range between 3 and 5 kg. Males are larger than females. All individuals have close-fitting moderate length hairs over most of the body, and elongated side-whiskers. The whiskers are usually a lighter color (white or pale yellow) and differ in length from individual to individual. The faces of vervet monkeys are usually sooty black. A defining characteristic of this species is the greenish color of the upper parts of the face, which is caused by the banding together of individual hairs with black and yellow strands. In males, the scrotum and surrounding areas are bright blue or a greenish color. (Hill, 1965; Parker, 1983)

  • Sexual Dimorphism
  • male larger
  • Range mass
    3 to 5 kg
    6.61 to 11.01 lb
  • Range length
    400 to 600 mm
    15.75 to 23.62 in

Reproduction

Females typically have few mates in their lifetime, whereas some males have numerous mates. (Sellers)

Little is known about the reproductive habits of C. aethiops; however, like most primates, they are cyclically receptive. Visual changes in the vulva of females, such as swelling, alert the males as to when the females are in heat.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • viviparous
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    162 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    1034 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    1825 days
    AnAge

Females take a strong interest in raising their young. Within the social groups, other females often share this task with the mother.

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • extended period of juvenile learning

Lifespan/Longevity

Behavior

These are highly social animals. They travel in small groups and are one of the few species to have multi-male groups. High ranking males demonstrate their place in the hierarchy by placing their tail in a stiffly upright position and strolling past lower ranking males. Vervets differ from other species in that they prefer open areas to forests and are very adept at traveling on the ground. Grooming is a common behavior among most primates, and C. aethiops is no exception. Grooming is commonly used as a courtship strategy. (Hill, 1965; Sellers)

Communication and Perception

Food Habits

Chlorocebus aethiops is omnivorous but with a heavy emphasis on fruit. Their diets often Include insects, vegetable matter, and at times, small mammals and birds. (Harris, 1970)

  • Animal Foods
  • birds
  • mammals
  • insects
  • Plant Foods
  • leaves
  • fruit

Predation

Vervet monkeys fall prey to leopards, snakes and raptors, as do other savanah monkeys. They may also be preyed upon by baboons.

Ecosystem Roles

As frugivorous monkeys, vervets may play some role in seed dispersal. Because they sometimes prey on other animals, they may act as a check on populations of certain insects, birds, and small mammals. As a prey species, they are likely to impact predator populations.

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Chlorocebus aethiops is separated evolutionarily from humans by more than 50 million years. Their resemblance to Homo sapiens, however, in characteristics such as the nervous system, reproduction systems, and suceptibility to certain parasites make them especially desireable for biological studies. (Harris, 1970)

  • Positive Impacts
  • research and education

Conservation Status

Chlorocebus aethiops is being threatened by continous deforestation and and destruction of their natural habitat. CITES Appendix 2. (Parker, 1983)

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Melissa Jill Rochester (author), University of Michigan-Ann Arbor.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

polygynous

having more than one female as a mate at one time

scrub forest

scrub forests develop in areas that experience dry seasons.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Harris, R. S. 1970. Feeding and Nutrition of nonhuman Primates. Academic Press, New York

Hill. 1965 Primates, Comparative Anatomy and Taxonomy. Volume VI. University Press, Edinburgh

Parker, S. P. (editor). 1983. Grizmeks Encyclopedia - Mammals, English Edition. McGraw-Hill Publishing Company, New York

Sellers, Dr. Bill. http://www.leeds.ac.uk/chb/lectures/anthl_11.html

Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press.