Colobus polykomos

Geographic Range

Individuals of the genus Colobus are typically found in tropical rain forests (lowland and montane types) of Africa, in the countries of Senegal, Ethiopia, Tanzania, Congo, Malawi, Uganda and Zambia. Colobus polykomos is limited to a range from Gambia to the Ivory Coast.

• Biogeographic Regions
• ethiopian ethiopian
  • native native

Habitat

Most African forests in which C. polykomos is found experience prolonged and pronounced dry seasons. Most of the forest lies within 10 degrees of the equator and is characterized by two rainfall peaks interspersed with two relatively dry periods--one short and one long. Much of the African moist forest zone is dominated by a single leguminous tree species. At present, much of C. polykomos habitat has been overrun by farming (especially rice cultivation) and tree cutting. This being the case, these areas typically support a variable array of young secondary forest. The old secondary forest (60% of the habitat) is dominated by the leguminous trees.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest
• rainforest rainforest
• scrub forest scrub forest

Physical Description

Males, on average, weigh approximately 9.90 kg, whereas a typical female is near 8.30 kg. Head and body length range from 450 to 720 mm, tail length from 520 to 1,000 mm. Colobus polykomos has white markings like most other species within the genus Colobus , however, this species is distinctive in that the chest and whiskers are white while the rest of the body is black. Further, the tail is entirely white and not tufted (Nowak, 1999). Colobus polykomos is slender- bodied with a long tail and prominant rump callosities. A complex sacculated stomach is present, but cheek pouches are absent. The thumb is reduced to a mere tubercle, the skull is somewhat prognathous, and the orbits are oval with narrow superciliary ridges (Nowak, 1999). The nostrils are lengthened by an extension of the nasal skin and may extend to nearly the mouth.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

The mating system has been described as 'unimale'--one male mating with several females, as well as 'multimale' where multiple males mate with multiple females.

• Mating System
• polygynous polygynous
• polygynandrous (promiscuous) polygynandrous (promiscuous)

There is conflicting evidence regarding seasonality of reproduction. In some groups, C. polykomos has been observed to give birth year round, but in others the birth season coincides with the dry season (December-May). This is thought to occur as a result of the greater availability of fruit as well as access to crops and human provisioning.

The gestation period of this species is 175 days on average, and the interbirth interval is approximately 24 months. Females, on average, produce 1 offspring every 20 months (Nowak, 1999) and reach sexual maturity at approximately 2 years of age.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

As in all primates, females are primarily responsible for the care of offspring. Females provide their young with milk, protection, and grooming. Young are not able to walk immediately, and must be carried for some time. The role of males in parental care has not been reported.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • protecting
    • female

Lifespan/Longevity

The maximum longevity reported for this species is 23.5 years in captivity. Wild life spans are not known with certainty, but are likely to be lower than this.

Behavior

Colobus polykomos typically live in small social groups comprised of 3 to 4 adult females and 1 to 3 adult males. The females maintain close spatial relationships with one another and engage in grooming behavior. Adult males rarely interact and display a clear dominance hierarchy.

During the infrequent encounters between groups, adult males engage in aggressive displays with one another. Some of this aggression occurs in the form of territorial calling, which is meant to be indicative of male strength and condition. The calling can also be evoked in other situations, such as when a predator is threatening the group. Generally, however, it is thought that the main purpose of calling is to maintain spatial distance between two groups or between male members within one group.

• Key Behaviors
• arboreal arboreal
• diurnal diurnal
• motile motile
• sedentary sedentary
• territorial territorial
• social social
• dominance hierarchies dominance hierarchies

Home Range

The range of C. polykomos averages 22 hectares with considerable overlap between groups.

Communication and Perception

Communication in most primates is complex, involving visual signals (such as facial expressions and body postures), vocalizations, and different forms of physical contact ( such reassurance gestures, aggression, grooming). It is likely that these monkeys employ all means of communication listed above.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Although C. polykomos is generally highly arboreal, members of this species are found to feed on the ground. Colobus groups typically have a daily foraging path of only about 500 meters. The diet consists mostly of leaves, but fruits and flowers can be more/less important depending upon the season (Nowak, 1999).

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Plant Foods
• leaves
• seeds, grains, and nuts
• fruit
• flowers

Predation

Predators of these colobus monkeys are not reported. However, because of the size of these monkeys and their arboreal habits, likely predators include raptors and leopards. Large snakes might also take young animals.

Ecosystem Roles

These monkeys probably have some impact on their ecosystem. As a potential prey species, the abundance of these monkeys may affect the abundance of predators. In addition, their reliance on leafy vegetations, fruits and seeds, may affect the plant community, especially by dispersing seeds.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

In the nineteenth century, C. polykomos was hunted by humans extensively for use of its fur . More recently, however, C. polykomos has provided little economic benefit for humans. They could be considered important in ways other than economically, however, due to the fact that they are ecologically, anatomically and socially interesting.

Economic Importance for Humans: Negative

Their numbers are so low as to have little to no effect on humans whatsoever.

Conservation Status

Colobus polykomos is considered to be highly endangered because of habitat destruction and hunting. Habitat destruction occurs through subsistance farming, commercial agricultural development and selective logging. Colobus polykomos is also extremely vulnerable to hunting by humans, both for their meat and fur.

Attempts at maintaining this species in captivity has largely failed, most probably because of their digestive peculiarities. Instead, it is important to manage C. polykomos habitat forests effectively and prevent any further habitat destruction in order to protect and conserve them.

Additional Links

Encyclopedia of Life

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Devon Landes (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

References

Davies, G., J. Oates. 1994. Colobine Monkeys . New York: Cambridge University Press.

Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition . Baltimore and London: The Johns Hopkins University Press.