Cercopithecus cephus

Geographic Range

Cercopithecus cephus is distributed in western Africa, south and east of the Sanaga River. Its southern and eastern limits are the banks of the Congo/Oubangi river system. However, the region where the Congo River empties into the Atlantic Ocean is no longer a barrier since this species in now found in northwestern Angola and eastern Democratic Republic of the Congo. It is not known when or how C. cephus was able to cross the river barrier at this location, but it is not found much further from this crossing point. Cercopithecus cephus occurs in Equatorial Guinea, Gabon, the Republic of the Congo, southern Cameroon, southwestern Central African Republic, northwestern Angola, and eastern Democratic Republic of the Congo.

• Biogeographic Regions
• ethiopian ethiopian
  • native native

Habitat

Cercopithecus cephus inhabits an array of forested regions including primary rainforests, secondary rainforests, and gallery forests.

• Habitat Regions
• tropical tropical

• Terrestrial Biomes
• rainforest rainforest

Physical Description

Cercopithecus cephus has a very colorful face, bluish to violet with a bluish-white crescented stripe below the naked nose. Beneath this “moustache” are black hairs along the border of the upper lip and bright yellow bushy whiskers on both sides of the face. The ears are black and the rest of the head is covered with blackish-brown hair. This blackish-brown hair extends dorsally and laterally, with the ventral region having ashy grey hair. The tail, which is longer than the rest of its body, is nonprehensile and is covered in coppery-red hair.

The average length of C. cephus is 520 mm (head to body) and its tail averaging 700 mm. The average mass is about 4 kg. The dental formula is 2/2, 1/1, 2/2, 3/3 = 32.

Females and males are alike in color. Cercopithecus cephus is sexual dimorphic in size with the female being relatively smaller.

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

• Sexual Dimorphism
• male larger

Reproduction

Mating in this species is polygynous, with one male generally mating in a group of 10 to 40 females. A female elicits copulation by directing her rump towards the male, informing him that she is ready for copulation.

In spite of this basic pattern, polygynandrous mating groups sometimes occur. The breakdown of the one-male group structure may lead to between 3 and 6 males attending a group of females on any one day. These males occasionally leave such groups for a few hours to court and mate females in neighboring groups. The presence of several males in the group coincides with elevated levels of sexual activity.

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

In the tropics, where there is little annual variation in day length and temperature, annual changes in rainfall and nutrition are most important in determining the reproductive events of C. cephus . In areas of high rainfall, some populations display year round mating and birth. The majority of the C. cephus population has a mating season centered around July, August, and September, with the birth season centered around December, January, and February. Mating and birth seasons usually last three months or less when there is one wet season, and three months or longer when there are two wet seasons each year.

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

Little is documented about the parental investment of C. cephus , but close relatives of moustached guenons produce young that are relatively well developed at birth with open eyes and the means to support their own weight and embrace their mother. Mothers typically care for their young, providing them with food and protection, for a year or longer. Males may be considered to play some role in parental care in that they contribute to the defense of the social group against predators and rival males. This may help to protect the offspring.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • male
    • female
• pre-independence
  • protecting
    • male
    • female
• maternal position in the dominance hierarchy affects status of young

Lifespan/Longevity

Little is known about the lifespan of C. cephus in the wild or in captivity. However, one known wild born C. cephus female lived in captivity for 31 years and it is estimated that it was as old as 36 years. Close relatives of moustached guenons have lifespans in the wild averaging 22 years.

Behavior

Cercopithecus cephus is diurnal and arboeal. These guenons move through the rainforest quadrupedally with great agility. Their sure-footedness in rapid flight through an arboreal habitat makes them remarkable tree to tree leapers. They can leap up to 20 meters without faltering in passing from one group of trees to another. Cercopithecus cephus is known to use regular routes through the branches, with each monkey following the next along the same path.

Cercopithecus cephus characteristically exists in two kinds of groups. One kind is a group comprising males only, and the other kind is a group of 10 to 40 females with one adult male. Sometimes the one-male group might have more males for a short period of time due to increased sexual activity. If female members of a group are unhappy with a male intrusion, or even a female intrusion, they defend the group and chase away the solitary intruder.

• Key Behaviors
• arboreal arboreal
• scansorial
• diurnal diurnal
• crepuscular crepuscular
• motile motile
• sedentary sedentary
• social social
• dominance hierarchies dominance hierarchies

Home Range

No information is available on the home range of moustached guenons. However, groups of the closely related Cercopithecus ascanius defend a home range of about 120 hectares. Moustached guenons probaby have somewhat similar home range sizes.

Cercopithecus cephus has a great curiousity that accounts for their frequent wandering, which leads them to explore the edges of the forest or along forest tracts where timber is being cut down.

Communication and Perception

Cercopithecus cephus uses a trilling call that is soft and oscillates in a descending pitch. These calls are emitted by subadults when approached by an adult, therefore communicating obedience.

Cercopithecus cephus uses staring as a threat display. In this case, a monkey fixes its eyes on another individual with eyebrows raised, scalp retracted, and facial skin stretched by moving the ears back. The color underneath the eyelids contrasts sharply with the adjacent facial color, contributing to the visual effect of this threat. Cercopithecus cephus also stares with its mouth wide open but the teeth covered. This threat expression is usually accompanied by bobbing the head up and down.

Cercopithecus cephus also uses a nose-to-nose greeting, where two monkeys approach each other and touch noses. Such greetings are frequently followed by play or grooming.

Although not documented for this species, many old world primates use some forms of scent-based communication. Cercopithecus cephus may use some chemical communication as well.

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

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

Food Habits

Cercopithecus cephus is primarily frugivorous. This species has adapted to live on the pulp of oil palm nuts, and as a result, it is only found in regions where there is a constant supply of this fruit. In order to compete effectively with other primate species, C. cephus arrives at a fruiting tree before dawn. Cercopithecus cephus may also feed on fruits in the early evening after other primate species have retreated. In addition to oil palm nuts, moustached guenons consume seeds, leaves, insects, and eggs.

• Primary Diet
• herbivore herbivore
  • frugivore frugivore

• Animal Foods
• eggs
• insects

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

Predation

Predators of C. cephus include leopards, snakes, birds of prey, and humans who occasionally capture these monkeys.

Male moustached guenons produce a distinctive warning tone, which is described as a sharp, staccato, rhythmically repeated bark. A ke-ke-ke call is also used by both sexes, which indicates fear.

Ecosystem Roles

Cercopithecus cephus is accompanied by sneaky and silent birds ( Tropicranus albocristatus cassini ), which benefit from the insects, numerous seeds, and other vegetable products disturbed by the monkeys. This is commensalism. Because C. cephus is a frugivore, it undoubtedly aids in the dispersal of the seeds of fruit trees.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Cercopithecus cephus is sometimes kept as a pet. This guenon is usually friendly toward humans and is full of curiosity. However, as is true of all wild animals, C. cephus can bite.

• Positive Impacts
• pet trade pet trade

Economic Importance for Humans: Negative

In the wild, C. cephus is not reported to have any adverse effects on humans. However, when kept as pets, their curiosity often leads these monkeys to destruction of property. As mentioned previously, they are also capable of biting.

Conservation Status

Cercopithecus cephus is not endangered.

Other Comments

Cercopithecus cephus is commonly called a moustached guenon or a moustached monkey.

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Juan Miretti (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor, Nancy Shefferly (editor), Animal Diversity Web.

References

Estes, R. 1991. The Behavior Guide to African Mammals . Berkeley, California: University of California Press.

Hill, W. 1966. Primates, Comparative Anatomy and Taxonomy . New York: Interscience Publishers, Inc..

Kingdon, J. 1988. A Primate Radiation . New York: Cambridge University Press.

MacDonald, D. 1984. Encyclopedia of Mammals . New York: Facts on File Publications.

Smuts, B., D. Cheney, R. Wrangham, T. Struhsaker. 1987. Primate Societies . Chicago, Illinois: The University of Chicago Press.

Vaughan, T. 1986. Mammalogy . Orlando, Florida: Harcourt Brace Jovanovich.

2006. "Human Ageing Genomic Resources" (On-line). AnAge Database. Accessed April 18, 2006 at http://genomics.senescence.info/species/entry.php?species=Cercopithecus_cephus .