Colobus, Guereza


Colobus guereza


Head and body length – 18 to 27 inches; tail length – 20 to 35 inches; weight – 15 to 30 lbs.  Coat: glossy black, face and callosities surrounded by white, U-shaped mantle of varying length on sides and rear of back, outside of thigh variably whitish, tails variably bushy and whitish or yellowish from the tip towards the base.   Newborns have a natal coat that is completely white, shorter, and downier than the adult coat.  This natal coat changes to the adult coat color between 5 to 10 months of age.  Infant skin lacks dark pigment at birth.  Their hands and feet turn black at approximately 3 months.  At birth, newborns are approximately 8 inches long and weigh less than 1 lb.

Family

Cercopithecidae

Order

Primate

Class

Mammal

Range

Guereza colobus monkeys inhabit equatorial areas of Africa - Nigeria, Cameroon, Ethiopia, Kenya, Uganda, Tanzania, N Congo, E Gabon, Central African Republic, NE Zaire, W Kenya, NW Rwanda, and S Sudan.

Habitat

Woodlands, wooded grasslands, and montane forests

Life Expectancy

Males: 17.7 years Females: 14.3 years

Sexual Maturity

Approximately 3-5 years

Diet

In the wild, they eat primarily leaf material, supplemented by fruits and seeds, In the Zoo, they are fed scientifically formulated chow supplemented with fresh greens, vegetables fruits and forage mix. Keepers provide fresh cut vegetation as part of their daily diet. The Guereza colobus monkey is the second most folivorous of all Colobus, of which there are 12 known species. Diets consist primarily of leaves (especially from Celtis durandii, the Hackeberry Tree) made up of the following types: about 58% young unripe leaves, 12.5% mature leaves, 13.5% fruits, 4% leaf buds, and 2% blossoms. This distribution is highly varied seasonally and geographically; and at times, mature leaves may account up to 34% of the diet. This species of colobus monkey seems to prefer leaves that are less susceptible to seasonal fluctuations. Water is obtained from the following sources: dew, the moisture content of the diet, and rainwater held in tree trunk hollows.

Status

IUCN - Least Concern, CITES - Appendix II, AZA - green SSP

Behaviors

Social Structure: Guereza colobus monkeys live in mixed-sex groups of 3 to 15 individuals. One adult male and three or four reproducing females with adolescents and infants is the typical composition of such family groups. Sometimes several males are present in mixed groups, but only temporarily. The fixed core of the mixed group consists of the females, who remain in their birth group for life. These females are thought to be close relatives that display their friendly intra-group relationships with mutual grooming and “infant transfer.” Parental Care: Infant transfer or allo-mothering is observed soon after birth. An infant is handled by multiple females and is carried as far as 80 feet away from its mother. A mother may even suckle the infant of another female and her own simultaneously. Reproduction: Females produce a single young after a 5-month gestation. Intervals between offspring are about every 20 months. Unlike females, young males leave their birth group before they reach sexual maturity. If a male does not leave voluntarily, the dominant male will force him out of the troop. When young males leave, they lead a solitary life or temporarily associate with other solitary males. Some black and white colobus monkey males eventually take over their own harem and create a new group. Communication: Territories of different troops may overlap marginally; males defend boundaries with leaps and cries, hand-to-hand communication, roars, and occasional chasing and fighting. . Additional displays of the white fringe fur flapping up and down serve as warnings to other monkeys. Some groups, however, do share water holes and other essential resources. Male Guereza colobus monkeys roar loud nocturnal and dawn choruses as a means of spacing groups. Five vocal sounds have been recorded: roars, snorts, purrs, honks, and screams. Special Notes: Guereza colobus monkeys are generally diurnal and arboreal residents of deep forests. When trees are not densely packed, they will feed and travel on the ground. They also inhabit dry, moist, or riparian forests that are either in lowlands or up to 10,825 feet above sea level. They are most abundant in secondary growth forests or along rivers. There is no true leader of a troop, but strong males usually take leadership roles. The species lives in well-defined territories of about 32-40 acres.

Adaptions

Hind legs are long and muscular for leaping and bounding amongst branches. Guereza colobus monkeys have only four digits on each hand; the thumb is absent or represented by a small phalangeal tubercle that sometimes bears a nail. The loss of the thumb may be an adaptation for quick movements through the trees. Members of the genus Colobus, which are in the subfamily Colobinae, are distinguished from members of the other subfamily, Cercopithecinae, by the absence of cheek pouches and the presence of prominent ischial callosities that are separate in females and contiguous in males. Ischial callosities allow animals to sit for long periods on slender branches without discomfort. The stomach of C. guereza is complex. It is subdivided by partition into two subregions. The upper region contains a neutral medium, which is necessary for the fermentation of foliage by anaerobic bacteria. The Guereza colobus monkey’s large salivary glands provide a buffer fluid between the two regions of the stomach. The large stomach capacity accommodates large volumes of relatively non-nutritious food. The slow passage of material through the stomach is essential for fermentation. In fact, the stomach contents may be equal to or more than 25% of the adult’s body weight. This adaptation allows this species to digest leaves more efficiently than any other primate. The bacterium in the upper region of the stomach breaks down cellulose and releases energy. It can also deactivate many toxins, allowing this species to eat plant items containing toxins. Plant defense compounds are found in all trees, but are found in higher concentrations in trees growing in nutrient poor soils. It is costly for trees in these areas to replace leaves eaten by plant-eaters. To obtain important minerals like calcium, potassium, sodium, magnesium, and copper, Guereza colobus monkeys eat soil.

Special Interests

Natural predators of the Guereza colobus monkeys are crowned hawk eagles, leopards, and chimpanzees.. Colobus means, “mutilated one”. It was given to them because they have no thumbs.

Folklore

The Masai and other East African tribal peoples have used the coat of the black & white colobus monkey as a “majestic” adornment since ancient times.

Conservation

There has been a drastic decline in colobus populations over the last 100 years. Colobus guereza are Appendix II in International Trade of Endangered Species (CITES), and IUCN gives them a low conservation rating. Population sizes of black and white colobus monkeys are currently declining in many localities due to hunting and deforestation by humans. Nevertheless, since 1934 it has been reported that black & white colobus monkeys are “not uncommon” in suitably protected habitats. For example, they are still abundant in most parts of their lowland ranges in Cameroon along the Nigerian border, and in East African reserves and parks. Although still abundant, there is the potential for extinction of eastern populations from the unrestricted fur and bushmeat trades.

Jacksonville Zoo History

In September 1977, three eastern black-and-white colobus monkeys arrived here for the first time. Unfortunately, all three died that same month. This species did not occur in the collection again until May 1996. They have successfully bred here.

Exhibit

Great Apes Exhibit Area