Chlorocebus sabaeusgreen monkey

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Geographic Range

Chlorocebus sabaeus (the green monkey) is found almost exclusively in West Africa. It ranges from Senegal to the White Volta River in Ghana and can be found in many other African nations. Chlorocebus sabaeus was introduced to the Caribbean islands during extensive slave trading in the 1600s. These islands include St. Kitts, Nevis, and Bardados. (Cawthorn Lang, 2001; Zinner, et al., 2009)

Habitat

Although green monkeys prefer specific environmental conditions, they easily adapt to a wide range of habitats. In Africa, green monkeys live south of the Sahara Desert in forests that border woody grasslands. These areas are normally characterized by low, bushy foliage and tall grasses. Green monkeys live near the edges of these transitional forests and can be found crossing savannas between forest edges. They avoid the interior of dense, wet forests. Green monkeys also have colonized coastal regions of West Africa, although this is a deviation from habitat norms. Recent habitat destruction and deforestation are thought to have contributed to these recent migrations. In the Caribbean, green monkeys occupy a variety of habitats including mangrove swamps, agricultural sectors, and highly populated urban settings. (Cawthorn Lang, 2001; Dunbar, 1974; Wolfheim, 1983; Zinner, et al., 2009)

  • Range elevation
    0 to 4500 m
    0.00 to 14763.78 ft

Physical Description

These medium-sized monkeys are covered in thick golden fur with a green tint, which is how they get their common name, green monkeys. The face is hairless, but is covered with dark blue skin outlined by a soft line of white fur. Like other monkeys, they have long, slender, semi-prehensile tails. Males and females are sexually dimorphic. Males can weigh between 4 and 8 kg and measure an average of 500 mm in length. Adult females normally weigh between 3.5 and 5 kg and measure approximately 450 mm in length.

Males have blue scrotal regions and distinctly red penises. The combination of colors is said to present a distinctive “red, white, and blue” display.

Green monkey locomotion varies little, regardless of habitat or substrate. In almost all circumstances, they travel quadrupedally on the ground or in tree canopies. Being relatively light, green monkeys are able to nimbly travel on the tops of branches using all four limbs. (Cawthorn Lang, 2001; Skinner and Smithers, 1990; Young, 1998)

  • Sexual Dimorphism
  • male larger
  • sexes colored or patterned differently
  • male more colorful
  • Range mass
    3.5 to 8 kg
    7.71 to 17.62 lb
  • Range length
    300 to 500 mm
    11.81 to 19.69 in

Reproduction

Green monkey social structure revolves around alpha males. These males control interactions and contact of males and females. The alpha male dictates which males mate with females in this polygynous mating system and dominate most of the matings. (Cawthorn Lang, 2001)

Green monkeys are seasonal breeders, breeding between April and June. In the area typically inhabited by green monkeys, these months are characterized by heavy rainfall. Abundant rainfall results in an exponential increase in available food and nutritional resources. It is thought that this particular breeding season is an adaptation to take advantage of abundant resources. Green monkeys breed approximately once a year. The time interval between each breeding attempt depends on the success or failure of the previous pregnancy. Females reach sexual maturity in 2 years and males in 5 years. Infant mortality is high, resulting in a loss of about 57% of all newborns. (Cawthorn Lang, 2001; Cheney, et al., 1988; Fairbanks and McGuire, 1985; Young, 1998)

  • Breeding interval
    Breeding occurs approximately once a year.
  • Breeding season
    Breeding is from April to July.
  • Range number of offspring
    0 to 1
  • Average number of offspring
    1
  • Range gestation period
    163 to 165 days
  • Average gestation period
    165 days
  • Range weaning age
    12 to 24 months
  • Average weaning age
    12 months
  • Range time to independence
    1 to 1 years
  • Average age at sexual or reproductive maturity (female)
    2 years
  • Average age at sexual or reproductive maturity (male)
    5 years

From birth, mothers are closely attached to their offspring. Mothers tend to their offspring for approximately 1 year until they are fully weaned and independent. (Cawthorn Lang, 2001; Cawthorn Lang, 2001)

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

Lifespan/Longevity

The lifespan of green monkeys has not been well studied. Green monkeys are heavily preyed on and affected by a variety of diseases. In captive conditions the lifespan ranges from 11 to 13 years. This is assumed to be the upper limit for age of green monkeys in the wild. (Fairbanks and McGuire, 1985)

  • Range lifespan
    Status: captivity
    11 to 13 years
  • Typical lifespan
    Status: wild
    13 (high) years
  • Typical lifespan
    Status: captivity
    11 to 13 years

Behavior

Green monkeys are highly social. Grooming behaviors and gender relationships suggest underlying social hierarchies. Total group number can vary greatly, from 7 to 80. Male and female green monkeys partake in inter-group emigration. After reaching sexual maturity, adults move from group to group with closely related family members. This helps to avoid predation, reduce inbreeding, and increase the spread of desired genes. Small overlaps of green monkey territory exist in many habitats. Alpha males establish dominance through physical fighting or scrotal displays. Dominance rank determines access to mates and resources. Green monkey alpha males limit the proximity of other males to females and defend their territory with physical aggression against alien males. Such encounters typically are limited by environmental conditions and resource availability. It is only when food or habitat becomes scarce that territorial encroachment occurs. (Cawthorn Lang, 2001; Cheney, et al., 1988)

Home Range

The home range of green monkeys has been estimated at from 0.05 to 2 square kilometers. (Zinner, et al., 2009)

Communication and Perception

Green monkeys are very vocal primates. Vocalizations serve mainly to alert local members to danger. Using distinct vocalizations, green monkeys are able to differentiate among various predators and levels of danger. Green monkeys have evolved a unique call for each predator. Males are also capable of communicating through body language. Using brightly colored genitalia, green monkeys can signal danger to other monkeys without vocalizations. This form of non-verbal communication is also a method of establishing social hierarchies and male dominance. A more subtle mode of communication is through facial expressions. Research demonstrates that facial expression is correlated with emotional state. Feelings of anger, elation, and even frustration are manifested in distinct facial expressions. It is possible that green monkeys use facial expressions to indicate danger or satisfaction, depending on the circumstances. (Cawthorn Lang, 2001; Cheney, et al., 1988; Peters and Ploog, 1973; Skinner and Smithers, 1990)

Food Habits

Green monkeys are both frugivorous and folivorous depending on the availability of leaves and fruit. Green monkeys adapt to available resources depending on the time of year and environmental conditions. During the dry season or after a fire, little fruit is available. Green monkeys forage across short expanses of grassland eating available plants. Nonetheless, fruits are preferred to leaves and less nutritious grasses commonly found in savannas. When rain is plentiful, fruits become more abundant. Fruits typically are collected in the trees and common fruit species eaten include wild bananas, papayas, and mangos. In the wild, green monkeys commonly use a mouth pouch to store and carry food as it is found. These pouches are present in all members of the Cercopithecoidea. This behavior protects valuable food from other consumers and allows green monkeys to continue collecting food for extended periods. (Dunbar, 1974; Young, 1998; Dunbar, 1974; Young, 1998)

  • Plant Foods
  • leaves
  • roots and tubers
  • fruit
  • nectar
  • flowers
  • sap or other plant fluids
  • Other Foods
  • fungus

Predation

In West Africa, leopards, martial eagles, and pythons are primary predators of green monkeys. In the Caribbean and the West Indies, humans are the only documented predators. (Cawthorn Lang, 2001)

Ecosystem Roles

Very little is known about the ecosystem role of green monkeys. However, they are highly frugivorous and likely play a large role in spreading seeds throughout the ecosystem. Also, their herbivorous diet competes with that of insects, birds, bats, and other species of primates. The large population density of green monkeys makes them accessible to many predators. Thus, they are a valuable source of food for other organisms including African cats, predatory birds, and sometimes baboons.

Documented cases of green monkey parasites are prevalent. Protozoan parasites and helminths (parasitic worms) are the most common and harmful organisms that plague green monkeys in the wild. (Bourliere, 1985; Legesse and Erko, 2004)

  • Ecosystem Impact
  • disperses seeds
Commensal/Parasitic Species
  • cryptosporidiosis (Cryptosporidium parvum)
  • parasitic worms

Economic Importance for Humans: Positive

Green monkeys and related species have been used extensively in biomedical research. Many studies have been conducted on the effects of infectious diseases on primate biology. Most notably, valuable advances in HIV/AIDS can be directly connected to experiments performed on green monkeys. (Carlsson, et al., 2004)

Economic Importance for Humans: Negative

In West Africa, humans rarely come into contact with green monkeys. In the Caribbean, green monkey populations have expanded due to a lack of natural predators. There, they are crop pests, foraging on fruit and other crops. (Boulton, et al., 1996; Cawthorn Lang, 2001)

  • Negative Impacts
  • crop pest

Conservation Status

Although green monkeys are not considered endangered, it is feared that continued hunting, trapping, and habitat destruction will drive populations to low levels in their native range in Africa. Continued research is being conducted in order to better understand the ecology of green monkeys and how to protect populations. However, in the Caribbean, where they are introduced, green monkeys are considered pests and populations have become dense in some areas. (Boulton, et al., 1996; Cawthorn Lang, 2001)

Other Comments

The taxonomy of green monkeys has recently been a topic of discussion. In the past, green monkeys and their close relatives were included in the species Cercopithecus aethiops. However, recently green monkeys received specific status. The generic name Cercopithecus is still mistakenly used in reference to green monkeys occasionally and is the name that was used in older literature. (Rowe, 1996; Cawthorn Lang, 2001; Rowe, 1996)

Contributors

Matthew Keller (author), Case Western Reserve University, Darin Croft (editor, instructor), Case Western Reserve University, Tanya Dewey (editor), Animal Diversity Web.

Glossary

Ethiopian

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

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

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.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

polygynous

having more than one female as a mate at one time

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

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.

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

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.

visual

uses sight to communicate

viviparous

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

References

Boulton, A., J. Horrocks, J. Baulu. 1996. The Barbados vervet (Cercopithecus aethiops sabaeus): changes in population size and crop damage. International Journal of Primatology, 17/5: 831-844.

Bourliere, F. 1985. Primate Communities: Their Structure and Role in Tropical Ecosystems. International Journal of Primatology, 6/1: 1-25.

Carlsson, H., S. Schapiro, J. Hau. 2004. Use of primates in research: a global overview. American Journal of Primatology, 63/4: 225-237.

Cawthorn Lang, K. 2001. "Primate Factsheets: Vervet (Chlorocebus) Taxonomy" (On-line). Accessed November 30, 2009 at http://pin.primate.wisc.edu/factsheets/entry/vervet/taxon.

Cheney, D., R. Seyfarth, S. Andelman, P. Lee. 1988. Reproductive success: studies of individual variation in contrasting breeding systems.. Chicago, IL: University Chicago Press.

Dunbar, R. 1974. Observations on the ecology and social organization of the green monkey,Cercopithecus sabaeus, in Senegal. Primates, 14/4: 341-350.

Fairbanks, L., M. McGuire. 1985. Relationships of vervet mothers with sons and daughters from one through three years of age.. Animal Behavior, 33/1: 40-50.

Legesse, M., B. Erko. 2004. Zoonotic intestinal parasites in Papio anubis (baboon) and Cercopithecus aethiops (vervet) from four localities in Ethiopia. Acta Tropica, 90: 231-236. Accessed December 05, 2009 at www.sciencedirect.com.

Peters, M., D. Ploog. 1973. Communication Amoung Primates. Annual Review of Physiology, 35: 221-242.

Rowe, N. 1996. The pictorial guide to the living primates. East Hampton, NY: Pogonias Press.

Skinner, J., R. Smithers. 1990.

The mammals of the southern African subregion, 2nd edition.
. South Africa: University Pretoria.

Wolfheim, J. 1983. Primates of the world: distribution, abundance, and conservation. WA: University of Washington.

Young, R. 1998. Behavioural studies of guenons at Edinburgh Zoo. International Zoo Yearbook, 36: 49-56.

Zinner, D., S. Gonedele, J. Koffi Bene, E. Anderson Bitty, I. Kone. 2009. Distribution of the Green Monkey (Chlorocebus sabaeus) in the Coastal Zone of Côte d’Ivoire. Primate Conservation, 24: 1-7.