| Chlorocebus, Primate, Vervet monkey, Guenon, Green monkey|
The grivet (Chlorocebus aethiops), also known as African green monkey and savanah monkey is an Old World monkey with long white tufts of hair along the sides of the face. Some authorities consider this and all of the members of the genus Chlorocebus to be a single species, Cercopithecus aethiops. As here defined, the grivet is restricted to Ethiopia, Sudan, Djibouti and Eritrea. In the southern part of its range, it comes into contact with the closely related vervet monkey (C. pygerythrus) and Bale Mountains vervet (C. djamdjamensis). Hybridization between them is possible, and may present a threat to the vulnerable Bale Mountains vervet. Unlike that species, the grivet is common and rated as Least Concern by the IUCN.
The grivet's facial skin, hands, and feet are black. The face has a white line above the eyes. It has long white whiskers on the cheeks. The fur on the back has an olive color, while the front is white fur. The skin on the stomach has a blue tint. The fur has a bristly feel. The approximate head and body length for males is 49 cm (19 in) for males 42.6 cm (16.8 in) for females. The length of the tail for males is approximately 30–50 cm (12–20 in). The body mass ranges from 3.4 to 8.0 kg (7.5 to 17.6 lb) with females at the smaller end of the scale.
The main habitat of the grivet is savanna woodlands. Its range is Sudan east of the White Nile, Eritrea, and Ethiopia east to the Rift Valley. It is also found in Djibouti and Eritrea. The grivet needs to live around a source of water, especially during the dry season. It is able to adapt to many environments.
The grivet is most active in the morning and in early evening. It stays on the ground most of the day to eat and at night it sleeps in trees. The grivet spends a lot of time grooming, playing, climbing, and play fighting; all of these things help to ensure its survival. Its eating habits consist of eating mostly fruits, vegetables, and sometimes small mammals, insects, and birds, making it an omnivore. It will also scavenge for human food. It must drink water daily, especially in the dry seasons. It is one of few species that has multiple-male groups that are of moderate size. In the hierarchy of males, an individual shows its dominance by putting its tail in a stiff upright position and strolling past lower-ranked males. They travel in packs and usually move on all fours or quadrupedally, except when using both hands for carrying, when they manage to walk and run quite comfortably on two legs. Groups can range from five to over 70.
Females will have a limited number of mates, while males will have numerous. Swelling of the female's vulva alerts males as to when the female is in heat. Giving birth to one baby at a time is common and the pregnancy usually lasts two to three months. When the baby is born the mother will clean the infant and bite off the umbilical cord. Young have pink faces and black hair. It will take around two months for them to get their adult coats. The first few months, the infant will stay very close to its mother, but after six months, the infant is weaned.
The grivet is occasionally hunted as bushmeat. They are killed for either commercial or subsistence purposes. Although not endangered, it is threatened through destruction of habitat by way of disappearing forests. It is preyed on by large snakes, leopards, humans and sometimes baboons. The grivet may live for 13 years.