Colobus, Angolan


Colobus angolensis


Black hair with a white brow band, cheeks, and throat. Long haired white epaulettes stream from the shoulders. The lower part of the tail is white as is the band (males have a band, females have a patch) on the buttocks.  Nails are flattened, buttocks are padded, and their hind legs are longer than their fore limbs.  Head-body length of 19.7 – 27.6 in; weight averages 15 – 30 lbs.

Family

Cercopithecidae

Order

Primates

Class

Mammalia

Range

Congo Basin to the south and northeast of the Congo River, as far as Ruwenzori, Burundi and southwestern Uganda; although named for Angola, it is rare in that country.

Habitat

Lowland and coastal rainforests

Life Expectancy

15.8 years

Sexual Maturity

3-5 years

Diet

In the wild, they feed predominantly on leaf material, supplemented by fruits and seeds. In the Zoo they are fed a scientifically formulated chow supplemented with fresh greens, fruits, forage mix and vegetables. Keepers provide fresh cut vegetation as part of their daily diet.

Status

IUCN – Least concern; CITES – Appendix II; AZA - green SSP

Behaviors

Social Structure: Females typically remain in their natal troops for life. The dominant male defends the territory and troop from predators whereas the dominant female leads the troop. Young males leave their natal troop to start bachelor groups or to travel alone until they are able to take over their own troop. They live in troops of up to 25 individuals, although temporary gatherings of over 300 have been observed. They typically live in relatively small social groups of one adult male and multiple females with offspring, however multi-male groups have been observed. Young males in the group are usually forced to leave before they reach breeding age but may also challenge the dominant male for control of the troop. Reproduction: Dominant adult males control reproductive access to the females within their family group. The gestation period ranges from 147 to 178 days and a single offspring is generally born, though twins are possible. Infants are born strikingly white, and then turn grey and black. By six months of age they change to the adult coloration of black and white. They are born throughout the year but a birth peak is seen in September and October. Parental Care: Colobus infants are known for their flamboyant coloration, which is remarkably different than the adult. This is considered an adaptation for encouraging allo-parenting by attracting other females in the group to the newborn. This supposedly frees up maternal time for feeding while other females care for the young. The nutritional value to their diet is low and the stress of rearing offspring puts enormous pressure on the female. Allo-parenting behavior thus counteracts the burden of nursing. Infants are weaned by 15 months of age. Communication: When a troop is threatened by a predator, the male jumps and roars until the rest of the troop has fled. Groups defend a relatively small core home range from other troops of Colobus monkeys. Morning roaring contests between dominant males may help to maintain group spacing. Special Notes: Angolan colobus are diurnal and highly arboreal, which may help avoid predators that feed at night. The leaping ability of Colobus are unsurpassed among other African monkeys. Wide gaps between trees are crossed by taking long leaps involving considerable vertical descent. Drops of nearly 50 feet (15m) into the undergrowth are made to escape predators. Displaying territorial males also make spectacular jumps. Although colobus can jump great distances on a falling leap, their ability to leap horizontally, although still impressive, is in question. The majority of their diet is made up of young and mature leaves - 46 species eaten but only five species make the greatest proportion of their diet. Because of the poor nutritional quality of their food, they browse intensively for many hours each day. They digest 4.5 – 6.6 lbs. (2-3 kg) of leaves per day (one third of their full body weight), and also eat seeds, unripe fruits, and flowers. Some species of Colobus are known to eat soil, clay, and charcoal, which are thought to assist in the digestion of toxic leaves.

Adaptions

Their stomach is large and has three chambers, which carries specific bacteria that help to ferment and digest leaves, similar to rumination of cows. Light-weight bone structure and elongated limbs are adaptations for arboreal living and makes it easier to leap from branch to branch. The reduction of the thumb is an adaptation to arboreal living as the fingers have become aligned into a single, narrow curved arc that allows the hand to act as a flexible hook.

Special Interests

Colobus have no thumbs though they retain an opposable big toe. Colobus in fact acquired their name from the Greek word “kolobos” meaning maimed or mutilated. Of all Colobus species, the Angolan Colobus occurs in the southernmost latitudes. They are less tolerant of cold temperatures than Guereza colobus, a colobus species that inhabits more northern geographic ranges.

Folklore

Conservation

Of the twelve currently recognized colobus species, one is near threatened, three vulnerable, three endangered, and two critically endangered. Angolan colobus are not currently considered endangered and may be fairly abundant in parts of their range. However, they are vulnerable to habitat destruction and have suffered extensively by hunting for bushmeat and skins, especially in highly populated areas. Populations are declining fairly rapidly in some areas such as the Kakamega forest in Kenya.

Jacksonville Zoo History

The Angolan colobus was a new first time species to the Jacksonville Zoo collection in 2008.

Exhibit

East African Exhibit Area