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Colobus vellerosus is also known by the common names: white-thighed colobus, Geoffroy's black-and-white colobus, white-thighed black-and-white colobus. This species was previously considered a part of the Colobus polykomos group.
Ursine colobus monkeys are social primates and have many vocal, tactile, and visual forms of communication. All Colobus species use a roaring call to advertise territory and location, it resembles a low "rur, rur, rur" noise (Fleagle, 1998). Colobus monkeys also have alarm calls that alert group members when predators have been seen. Alarm calls are characterized as "snorting" and are made by all members of the group except infants. As in other primates, mutual grooming is important to social cohesion ursine colobus monkeys and pheromones and scents aid in recognizing sexual state, age, and status of individuals.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Populations of ursine colobus monkeys have declined throughout their relatively small range. These monkeys are threatened by habitat destruction and are hunted regularly by a growing human population. They are listed as vulnerable by the IUCN, protected under Appendix II of CITES, and are protected under Class A of the African convention. Populations have become rare even in national parks and declines of 30% in the last 30 years have been estimated. These are now considered rare monkeys in Togo, Benin, Nigeria, and Ghana.
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: vulnerable
There are no known adverse effects of Colobus vellerosus on humans. Like all primates, they may transmit disease to humans, but this has not been reported in C. vellerosus and there is little contact between their populations and humans.
Ursine colobus monkeys are hunted for their fur and meat. They may play a role in forest regeneration through seed dispersal.
Positive Impacts: food ; body parts are source of valuable material
Ursine colobus monkeys are prey to some top predators in their forest ecosystems. They may also help to disperse the seeds of forest trees that they eat.
Ursine colobus monkeys are mainly folivorous and have a diet that consists of immature leaves and seeds. They also occasionally eat fruits, insects, and termite clay (Primate Info Net, 2008).
Animal Foods: insects
Plant Foods: leaves; seeds, grains, and nuts; fruit
Primary Diet: herbivore (Folivore , Frugivore , Granivore )
Colobus vellerosus is currently found in six countries throughout West Africa; Benin, Ivory Coast, Ghana, Nigeria, Togo, and Cote d’Ivoire.
Biogeographic Regions: ethiopian (Native )
Ursine colobus monkeys are forest dwellers inhabiting lowland forest, deciduous gallery forest, and savanna forest up to 350 meters elevation above sea level.
Range elevation: 350 (high) m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; rainforest
Other Habitat Features: riparian
Longevity in Colobus vellerosus is not reported in the literature. However, other colobus monkeys can live into their 20's in the wild and to about 36 years in captivity. Infant mortality rates are reported to be high.
Colobus vellerosus was once considered part of the Colobus polykomos group, but has been considered a distinct species since 1983 (Primate Info Net, 2008). Of the five species of colobus, Colobus vellerosus is distinctive, with predominantly black fur and no white mantle (Fleagle, 1998). The face is black and naked and surrounded by a thick white outer ring of fur. Colobus vellerosus is also characterized by white areas on the thighs that vary in width and length. As in other species of colobus, infants are born with an all white fur coat, which starts to turn black at around three months of age. Also as in other species of colobus, C. vellerous has obsolete thumbs which are just short nubs with nails on them. Which is thought to be an adaptation for better movement through trees. The fingers are long and take the form of a hook to improve grip when grabbing onto branches (Sai, et al., 2006). In comparison to other species of colobus, they have slender bodies and ischial callosities, a hard thickened area of skin on the buttocks that allows comfortable sitting on branches (Estes, 1991). The tail of Colobus vellerosus differs from other species in coloration. Where most other species have predominantly black tails with a bushy white tip, Colobus vellerosus has an all white tail that is usually longer than the body. The weight range is 9.9 to 10.3 kg for males and 8.3 to 8.7 kg in females. Body length is 61 to 66 cm in males and 61 to 64 cm in females (Primate Info Net, 2008). Colobus species are distinguished from other Cercopithecinae by their lack of cheek pouches and their large salivary glands (Fleagle, 1998). They have highly evolved large stomach that is used in the process of breaking down cellulose. The stomach always contains undigested food and can constitute up to a quarter of an adult’s weight (Estes, 1991).
Range mass: 8.3 to 10.3 kg.
Range length: 61 to 61 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic
Sexual Dimorphism: male larger
Some predators of ursine colobus monkeys are large raptors, such as crowned hawk eagles (Stephanoaetus coronatus), leopards (Panthera pardus), and humans. Humans threaten these monkeys through habitat destruction, forest fragmentation, and hunting for meat and fur (Sai et al., 2006). Subsistence farming, commercial agriculture development, and selective logging have all contributed to the decline of this species (Marteinson, et al., 2005).
Known Predators:
As in other species of colobus monkeys, Colobus vellerosus is polygynous. There seem to be no physical characteristics that make it evident when a female is in estrus (Teichroeb and Sicotte, 2008).
Mating System: polygynous
There is relatively little information on reproduction in Colobus vellerosus. Ursine colobus monkeys give birth to a single infant. Mating is evidently not strictly seasonal as births occur year round. More births occur around the rainy season due to abundance of vegetation, which allows the mother to provide plenty of nutrients to her infant (Teichroeb and Sicotte, 2008). Breeding occurs in 20 month intervals and gestation is about 5 to 6 months (Teichroeb and Sicotte, 2008). Time to weaning is not reported, but is from 8 to 15 months in other colobus monkeys. Females mature by four years of age and males by six years of age.
Breeding interval: Breeding occurs in 20 month intervals.
Breeding season: Births can occur year round, but are concentrated in the wet season.
Range number of offspring: 1 (low) .
Range gestation period: 5 to 6 months.
Average age at sexual or reproductive maturity (female): 4 years.
Average age at sexual or reproductive maturity (male): 6 years.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Female ursine colobus monkeys nurse, protect, and care for their young to independence. Other members of the group care for and handle infants as well. Members of the group handle infants carefully, but there is still a high mortality rate among infants (Brent et al., 2007). Females remain in their natal group. Male parental care is not reported in Colobus vellerosus.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); post-independence association with parents
