Vervet (Green) Monkey

ORDER: Primates

FAMILY: Cercopithecidae

GENUS: Chlorocebus

SPECIES: sabaeus

Stocky, green guenon. Head and body length 18-26in Weight 7.25 to 10 pounds. Usually yellowish to olive green coat with white underparts and gray lower limbs. Face black with white cheek-tufts and browband. Both sexes have long, sharp canines.

The most widespread African guenon (there are up to 20 subspecies), occurring throughout the Northern and Southern Savanna, from Senegal to Sudan and south to the tip of South Africa. Adapted to practically all wooded habitats outside the equatorial rain forest. Being small and not a fast runner, this monkey cannot afford to venture far from the safety of trees. It is essentially an edge species and typically associated with riverine forest; in the dry savanna, they stay near the acacias. Colonies have been established on St. Kitts, Nevis, and the Barbados Islands in the West Indies-probably descended from pets.

Omnivorous. Opportunistic omnivore which takes what is most abundant and available. Fruits, flowers, seeds, seed pods, leaves, grasses, and roots. On occasion, birds, eggs, small reptiles and insects.

Diurnal; most active in early morning and late afternoon. Territorial, but generally avoid serious conflicts (defend with loud barking and displays). Mainly ground dwellers, but take shelter in the trees when alarmed and sleep in trees. Usually found in groups of 20-50. Social structure is similar to other Old World monkeys in that the stable core of any group consists of several families of closely related adult females and their dependent offspring. Females stay in the natal group; males transfer to a neighboring group at adolescence. To minimize aggression from the transferred-to group, many males transfer in the company of age mates or maternal brothers. Males transfer groups several times during their lives. Sub adult females reciprocate their mother's grooming, join her in the formation of alliances, and serve as temporary caretakers of their mother's subsequent offspring. As a result, bonds are formed not only between mother and offspring but also among maternal siblings. Adult males interact only rarely with infants and show no special preference for those infants that are likely to be their offspring. High-ranking males are unable to maintain exclusive access to females around the time of ovulation, so paternity is uncertain. Infants acquire the rank of their mother's family. Older females maintain and acquire their dominance rank not by size or aggressiveness, but by size of their family and/or alliances formed. Male dominance rank is acquired by size, strength, and other determinants of fighting ability and is much less stable than female dominance rank. Guenons breed throughout the year, but most births are concentrated just before the rainy season, so that lactation proceeds when food and water are more abundant. Gestation lasts 163 days. They reach sexual maturity at the age of 4-5 years. Record life span in the wild is 17 years; up to 30 years in captivity.

The tail is well developed and used for balance. They are good swimmers.

Also known as vervet or grass monkeys. They have a creaking cry and a staccato bark that enables members of a troop to keep in contact. They have a variety of alarm calls, distinguishing between avian, snake or mammalian predators. Grooming removes parasites, but the primary function is to establish and maintain social bonds. It is most common among family members, but is also considered a means to form alliances with non-kin and to strive for higher status.

The green monkeys can be found in the African Savanna.

Although some species of guenons are listed as endangered or vulnerable, C.sabaeus is not, but numbers are declining because of destruction of forest habitat and excessive hunting by people. Listed as a species of Least Concern by IUCN.


  1. Cheney, D. & Seyfarth, R.1990. How Monkeys See the World. University of Chicago Press, pp.19-57.
  2. Estes, Richard, 1991. Behavior Guide to African Mammals. University of California Press, pp.501-509.
  3. MacDonald, David. 1987. The Encyclopedia of Mammals. Equinox, Oxford.
  4. Novak, Ronald. 1999. Walker