The mantled guereza (Colobus guereza), also known simply as the guereza or the abyssinian black-and-white colobus, is a colobus monkey. It is a kind of Old World monkey. It is native to much of west central and east Africa, including Cameroon, Equatorial Guinea, Nigeria, Ethiopia, Tanzania, and Chad.
This black-and-white colobus species grows to about 18 to 28 inches, with a 20 to 35 inch tail. It weighs 12 to 32 pounds. It has no cheek pouches, and, like most colobi, the thumb is nearly absent. Its coat is a glossy black with its face and rump surrounded by white. It has a U-shaped white mantle on its sides and rear of back. Its tail is white at the end. Young are all white. The point of its nose nearly touches its mouth. Its hind legs are long and well muscled for leaping through the trees and bounding along branches. Its rump calluses allow it to sit for long periods of time on slender branches without discomfort.
It lives in the uppermost branches of tropical forests, woodlands and wooded grassland (where it may travel on the ground). It stays in lowlands and high elevations. It is most abundant in secondary forests or along rivers. The mantled guereza’s digestive system is designed to process leaves. Its stomach is enlarged, specialized and contains bacteria for fermentation. It will also occasionally eat flowers, twigs, buds, seeds and shoots. Fruit makes up about a third of its diet.
Troop size of the mantled guereza is usually 6 to 9, with one or more adult males. Its home range is about 40 acres. This species has a preferred area within its home range from which other groups are chased, but not permanently excluded. Visual and vocal displays occur when groups meet. Loud nocturnal and dawn choruses by adult males serve to space out groups.
Single young born after a 5-month pregnancy, with offspring are produced about every 20 months. Young become fully mature in about 4 to 6 years. Their life span in captivity is upwards of 23 years.