Colobus Monkeys

The black and white colobus monkeys of central Africa (genus Colobus) have the least visible thumb of any genus in the subfamily Colobinae, although what little thumb remains has a nail on it. These monkeys have slender bodies, bare faces, and long tails with a puff of long fur on the end. Head and body length is 17.7-28.3 in (45-72 cm), tail length is 20.5-39.3 in (52-100 cm), and weight is 11.9-31.9 lb (5.4-14.5 kg).

The five species in this genus are distinguished by the amount of white markings and by the placement of long silky strands of fur in different locations. The black colobus (C. satanus) has a completely black, glossy coat. Colobus polykomos has a white chest and whiskers and a white, tuftless tail; C. vellerosus has white thigh patches, a white mane framing its face, and a white, tuftless tail; C. guereza has a flat black cap over a white beard and "hairline," a long white mantle extending from the shoulders to the lower back, and a large white tuft on its tail; C. angolensis has long white hairs around the face and on the shoulders, and a white tuft on the end of its tail.

Black and white colobus monkeys are typically highly arboreal (tree-dwelling) inhabitants of deep forests, but some species feed and travel on the ground where the trees are more widely spaced. When they sit still in the trees, these monkeys are well camouflaged because their black and white color blends with the patches of sunlight and shadow. When moving in the trees, colobus monkeys tend to walk along branches, either upright or on all fours, instead of swinging beneath them, and they often make amazingly long leaps from tree to tree. Their long hair apparently acts as a parachute to slow them down.

Black and white colobus monkeys often live in small social groups, consisting of both males and females. For example, C. guereza lives in groups of 3-15 individuals; most groups have a single adult male and several adult females with their young. The female membership in these groups seems stable, but adult males are sometimes ousted by younger males. Relations among members of the same group are generally friendly and are reinforced by mutual grooming.

Black and white colobus monkeys can apparently breed at any time of the year. Females become sexually mature at about four years of age, while males reach sexual maturity at about six years of age. Each pregnancy results in a single offspring. Infants are born with all white fur, which is shed before the regular coloring comes in. Child rearing seems to be shared among the females in the group.

All species of black and white colobus monkeys have declined over the last 100 years due to hunting for meat and the fur trade, the rapid expansion of human populations, and habitat destruction by logging or agriculture. The skins of black-and-white colobus monkeys were often used for clothing in Europe during the nineteenth century. They were still available as rugs in the early 1970s. The pelts of as many as 50 animals might have been used to make a single rug. The black colobus (C. satanus) is classified as vulnerable by IUCN—The World Conservation Union. Its continued survival is threatened by hunting and habitat disturbance and destruction.