By Karen Kennedy
Geographic Range
Cercopithecus diana is distributed from Sierra Leone to Ghana, in Western Africa.
Habitat
Diana monkeys dwell in upper levels of primeval forest trees. They sleep in trees in closed forest canopies, and never make nests.
These animals are found in the following types of habitat:
tropical 
; terrestrial .
Terrestrial Biomes:
forest ; rainforest .
Physical Description
(8.8 to 15.4 lbs)
Cercopithecus diana ranges from 40 to 55 cm in length, with a long tail 50 to 75 cm long. The coloration is extremely variable. These primates are generally black, with a white throat, ruff, pointed beard, and anterior side of arms. A white stripe runs down the thighs (Kingdon 1989). The posterior back and thighs are red-brown to orange (Grzimek 1990). Cercopithecus diana is catarrhine, with the nostrils close together and facing downward. The nail on each digit is flattened. The hallux and pollex are opposable. Prominant calluses, or ischial callosities, are present on the rump. The dental formula is 2/2, 1/1. 2/2, 3/3=32 (Vaughan 1986).
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Reproduction
Because these animals breed seasonally, and given the long period of infant dependence, it is likely that females are only bale to produce once per year.
Copulations are probably times so that the young are born at the period of maximum food availability.
Diana monkeys have a polygynous mating system. Courtship is short, since mates are usually familiar with each other. The female presents her rump prior to copulation in an appeasement gesture to signal readiness and vulnerability (Vaughan 1986).
Mating systems:
polygynous .
Diana monkeys breed seasonally. They are polyestrus, with an approximately 31 day cycle. The gestation period lasts 5 months (Cockrum 1962). Females give birth to one or rarely two young at a time. The young are weaned at about six months and reach sexual maturity at about three years (Grzimek 1990).
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous .
The young are relatively well developed at birth, with open eyes and the capability to grasp the mother and support their own weight (Macdonald 1984). Females nurse and care for their offspring for about six months. Daughters stay with their mothers as long as they live, whereas males leave the natal group near the time of adolescence (Macdonald 1984).
Parental investment:
precocial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (provisioning: female, protecting: female); post-independence association with parents; extended period of juvenile learning; maternal position in the dominance hierarchy affects status of young.
Lifespan/Longevity
These animals are thought to reach a maximum age of about 20 years.
Behavior
Cercopithecus diana is arboreal and diurnal. Diana monkeys are social, living in groups of 15 to 30 individuals with a single adult male. These monkeys communicate with one another with calls and visual cues. The well developed facial muscles along with the coloration allow a wide range of facial expressions for communication. These monkeys may "grin" in appeasement to dominating individuals (Vaughan 1986). Their vocal communication includes general vocalizations, alarm and contact calls.
The young play constantly, learning to be agile and swift in the trees. (
http://www.uni.edu/museum/cercopan/guenons.html)
Home Range
The territory size is between 0.5 and 1 square km.
Communication and Perception
As in all primates, communication is likely to be varied and complex. Facial expression and body postures are some of the visual cues primates use to communicate mood and intent. Vocalizations are common in primates. Tactile communication is important in social bonding and maintenance of relationships. Grooming, mating, and caring for young are all very tactile.
Food Habits
Diana monkeys are omnivorous, eating fruits, flowers, young leaves, insects and invertebrates (Grzimck 1990, Macdonald 1984).
Primary Diet:
omnivore .
Animal Foods:
insects; terrestrial non-insect arthropods.
Plant Foods:
leaves; fruit; flowers.
Predation
As is common in other forest monkeys, predators are likely to include leopards, snakes, and birds of prey.
Ecosystem Roles
As a prey species, these monkeys are likely to have an impact on predator populations. As fruit eaters, they are likely to help disperse seeds.
Key ways these animals impact their ecosystem:
disperses seeds.
Economic Importance for Humans: Negative
Diana monkeys can carry and spread diseases like yellow fever and tuberculosis (Macdonald 1984).
Economic Importance for Humans: Positive
Diana monkeys are used for food, pets, and in medical research (Macdonald 1984, Lawlor 1979).
Conservation Status
The current status of C. diana is CITES-Appendix I; US ESA- Endangered, IUCN- vulnerable (Wilson and Reeder 1993). Diana monkeys are seriously threatened by hunting and by destruction of forests (Grzimck 1990). One subspecies, C. diana roloway, is recognized; it lives in the Ivory Coast and Ghana.
Other Comments
The life span of C. diana may exceed two decades.
For More Information
Find Cercopithecus diana information at
Contributors
Nancy Shefferly (editor), Animal Diversity Web Staff.
Karen Kennedy (author), University of Michigan.
