Classification and Range
DeBrazza's guenons (African forest monkeys) are classified in the order Primates, and within the family Cercopithecidae. There are 18 genera in this family, including the genus Cercopithecus. There are 19 species within this genus, including the DeBrazza's guenon (Cercopithecus neglectus). Common names vary—they are sometimes called DeBrazza's monkeys.
They range from southeastern Cameroon eastward through the Central African Republic, Zaire, Burundi, Rwanda, Uganda and western Kenya, northward to Ethiopia and Sudan. They are also found in northern Angola, Gabon and Equatorial Guinea.
DeBrazza's guenons prefers dense swamp, bamboo and dry mountain forests associated with streams, rivers and dense vegetation. They are found at elevations up to 6,890 feet (2,100 m).
Their gray-green coloring offers excellent camouflage from predators such as leopards, eagles, pythons and other primates. Adults are nearly identical in appearance, each having distinctive white lip whiskers and long beard, and a orange-red crescent-shaped patch on the brow. They have a white rump and white thigh strip. Individual animals recognize each other by variations in patterns around the face, and at times on the rear. Males have a bright blue scrotum.
The average weight for a male is 15 pounds (7 kg), female weight is approximately 10 pounds (4.5 kg). Males are noticeably larger than females. Male head and body length is 19-23.5 inches (47.5-52 cm); tail length is 23-31 inches (57.5-77.5 cm). Female head and body length is 15.5-21.5 inches (39-54 cm); tail length 18.5-22.5 inches (46-56 cm). Their tail length is longer than their combined head and body length.
Life span in the wild up to 22 years; in captivity up to 30 years.
In the wild:Up to 75% of their diet are fruits and seeds. They also consume leaves, mushrooms, flowers, and small animals such reptiles and arthropods.
At the zoo: Greens, fruits and monkey biscuits.
DeBrazza's guenons reach sexual maturity in 5 to 6 years. They have a primarily polygynous mating system, although some appear to be monogamous. They are the only Old World monkey known to practice monogamy. DeBrazza's guenons breed throughout the year. After a gestation period of about 168-187 days, a single infant is born; twins are rare.
Newly born infants are born with eyes open and covered with light brown fur. Infants cling tightly to their mother's stomach for security and protection from predators. Although they are not weaned for about a year, young do begin to nibble solid foods after about 2 months of age.
Although a troop can number up 35 individuals, 10-15 is more common. Troops are normally comprised of one dominant male, one or more females and their young. Smaller family groups of one male and one female are not uncommon. Females may stay with their troop for their entire lives. Younger males that have not achieved full adult coloring can also remain with their troop.
Troop territories overlap, with no known territorial defense between DeBrazza's guenon troops. Males become very territorial when another monkey species approaches their food trees. Fights are not uncommon, and the whole troop may take part in forcing the intruders from their territory.
DeBrazza's guenons are diurnal, spending the majority of their time low in the forest canopy or on the forest floor eating berries, leaves, fruits and invertebrates. Foraging normally takes place around dawn and dusk. They have cheek pouches in which they quickly store food with their hands as they forage in exposed areas. Only later, when they are in a safe area will they take the time to eat their food.
What a Face
The French word guenon means ""fright", and refers to the variety of facial expressions this animal uses, in various combinations, to threaten or when anxious. To threaten they can stare with fixed eyes, raised eyebrows and stretched back facial skin, they may stare with open mouth, or they might bob their head up and down, or yawn and expose their large canines. A submissive signal might be retracted lips to bare their clenched teeth. Head-shaking also takes place when tension is high within the troop.
Call of the Wild
Males are by far the noisier sex. The troop leader can produce a deep, humming boom, which is enhanced as he inflates his vocal sac. The male also has a couple methods for warning troop members of the approach of a predator. He may produce a loud chattering bark, quickly followed by single barking croaks. Or he may loudly shake the branches of a tree. These actions are believed to be attempts by the male to draw the predator's attention away from the troop. As a last resort, the male may even attack the predator in defense of this troop.
Location at the Zoo
DeBrazza's guenons are not currently being exhibited. Other species you will find as you stroll through the outside portion of the Tropical Rain Forest are the red-flanked duiker, black & white colobus, and western lowland gorilla.
Throughout the majority of its range, DeBrazza's populations are at a healthy level. Their numbers, however, have drastically dropped in recent years in some areas. This is primarily due to the fragmentation of its habitat caused by the clearing of forests for agricultural expansion or commercial logging. Their capture for the pet trade is also having an impact. Recent escalation of logging and bush meat trade, however, poses a potential threat to their survival throughout their range.
Many international organizations are working with African countries to establish and secure wildlife habitats, and to curb the rampant bush meat trade. In North America, the Association of Zoos & Aquariums' (AZA) Species Survival Plan (SSP) manages the population of this species.
How You Can Help!
The effort to save African mammals requires cooperation and support at the regional, national and international levels. You can help in this cause. Join and become active in a conservation organization of your choice. Don't buy products made from wild animal parts. Tell your elected representatives on the national, state and local levels about the importance of preserving wild habitats and endangered species.
Contact Woodland Park Zoo at firstname.lastname@example.org to find out about ways you can support conservation programs at the zoo. Learn other ways you can help conserve wildlife and the habitats they require for survival by visiting our How You Can Help page.
Sources and Suggested Reading
Estes, R.D. 1991. The Behavior Guide to African Mammals. University of California Press, CA.
Kingdon, Jonathon. The Kingdon Field Guide to African Mammals. Academic Press, Harcourt, Brace and Company, Publishers, New York, NY. 464 p.
Nowak, Ronald M., ed. 1991. Walker's Mammals of the World. 5th Edition. The John Hopkins University Press, Baltimore and London. 1,629 p.
Rowe, Noel. 1996. The Pictorial Guide to the Living Primates. Pogonias Press, East Hampton, New York, NY. 263 p.