Vervet Monkey (Green Monkey)
|Scientific Name:||Chlorocebus sabaeus|
|Height:||18-26 inches||16-24 inches|
|Weight:||7.5-10 pounds||6.5-8 pounds|
|Maturity:||5 years||2 years|
Lifestyle and Lifespan
|Gestation:||Gestation last about 163 to 165 days|
|Lifespan in the Wild:||17 years|
|Lifespan in Captivity:||30 years|
|Vervet monkeys are found in West Africa, from Senegal, Guinea-Bissau and Sierra Leone along the west coast, east to Ghana, Burkina Faso and southwestern Mali. The White Volta River in Ghana is the easternmost border of their range. They were introduced to St. Kitts, Nevis, and the Barbados Islands in the Caribbean.|
|Status in the Wild:|
It is a stocky, medium-sized monkey with yellow to olive green fur all over their back. Underparts are covered with white fur, and lower limbs are gray. Their face is furless and black, with white cheek-tufts and browband, brown eyes. Their tail is long and slender and semi-prehensile. Males have blue scrotal regions. Both sexes have long, sharp canines.
: Confusingly, the terms 'green monkey' and 'vervet monkey' are sometimes used for the whole genus of Chlorocebus, of which there are six speices including Chlorocebus sabaeus. Specifically, those terms reference the two species Chloroebus sabaeus and Chlorocebus aethiops. C. sabaeus is sometimes categorized as a subspecies of C. aethiops, though the IUCN regards them as a distinct species.
The greenish tinge to the Vervet Monkey's fur helps it camouflage in the trees.
Vervet monkeys are adapted to practically all wooded habitats outside of the equatorial rain forest. They are an edge species typically associated with riverine forest; in the dry savanna, they stay near the acacias.
The home range of Vervet Mokeys has been estimated at 0.05 to 2 kilometers squared.
Vervet Monkeys are opportunistic omnivorous, eating whatever is most abundant. The bulk of their diet consists of fruits, flowers, seeds, seed pods, leaves, grasses, and roots. They also will eat birds, eggs, small reptiles and insects on occasion.
Vervet monkeys are seed dispersers, helping replant their ecosystem. They are prey to pythons, eagles, leopards, hyenas, and lions.
Activity and Behavior
They are most active in the early morning and late afternoon. They will retreat to trees if danger is present, and sleep or nap in the trees as well.
The Vervet Monkeys communicate vocally, through body language, and facial expressions. There are able to differentiate between predators and each predator is assigned a unique alarm call, which alerts other monkeys in the group to what predator and how to get to safety. Males also use nonverbal communication by using their brightly colored genitals to signal to establish social hierarchy and male dominance.
Vervet Monkeys are highly social and have complex social groups of as many as 50 individuals. The core group consists of several families of adult related females and their dependent offspring. Adult males are unrelated, as they leave their natal group at maturity. When they leave, they often travel with other similar-aged males or brothers from their natal group. This reduces the threat of predation and aggression from the group they transfer to, and helps ensure genetic diversity and avoids inbreeding. Males may switch groups several times throughout their lives. Females and males have separate hierarchies. Infant females acquire their mother's ranks, and older females maintain and acquire dominance based on the amount of alliances they have made and the size of their families. 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 long 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.
Female vervets have a reproductive cycle similar to human women, rather than going into estrus, they have menstrual cycles that last approximately a month. Because of this, there is no yearly breeding season and females may give birth throughout the year. Typically, births are concentrated just before the rainy season so that lactation may proceed while food and water are abundant. High-ranking males may try to maintain exclusive access to females during their ovulation time, but are unable to do so and therefore paternity is uncertain.
Usually only one infant is born at a time. Offspring stay with their mother for up to a year before they are fully weaned and independent. Care for the offspring comes from the mother and older female siblings. Mortality rate of infants is 57% in their first year.
Listed as Least Concern on the IUCN and on Appendix II of CITES
Not much is known on historical information of the Vervet Monkey
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This is a monkey of many names! It is known as the Green Monkey, the Vervet Monkey, or the Grivet or Savanna Monkey. Often times, the entire genus is refered to as Green or Vervet Monkeys, as well as Guenons.
One form of nonverbal communication Vervet Monkeys engage in is tail position; this indicates rank in the social hierarchy. The more dominant an individual is, the higher they will hold their tail.
Vervet Monkey females have menstrual cycles just like human women. Just like women, they will undergo ovarian senescence (menopause). Vervet Monkey females reach ovarian senescence between 20 and 23 years of age.
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.
Atkins, Hannah M., Cynthia J. Willson, Marnie Silverstein, Matthew Jorgensen, Edison Floyd, Jay R. Kaplan, and Susan E. Appt. "Characterization of Ovarian Aging and Reproductive Senescence in Vervet Monkeys (Chlorocebus Aethiops Sabaeus)."Comparative Medicine 64.1 (2014): 56-62. Print.
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