Cercopithecus sclateriSclater's guenon

Geographic Range

Sclater's guenon, Cercopithecus sclateri, is restricted to floodplain forests between the Niger river and the Cross river in southeast Nigeria. Eleven small populations have been confirmed to exist. Populations are known to exist in the states of Akwa Ibom, Enugu, Imo, Abia and Cross River State. The localities known for this species include Utuma, Stubbs creek, Akpugoeze, Osomari, Lagwa, Blue river, Enyong creek/Ikpa river. (Baker and Tooze, 2003; Oates, et al., 1992; Oates, 1996; Stewart, 1996)

Some authors have speculated that C. sclateri may be a hybrid between Cercopithecus erythrotis, which occurs on the eastern side of the Cross river in Nigeria and Cameroon, and Cercopithecus erythrogaster which occurs on the western side of the Niger delta in Nigeria. Several authors, however, agree that C. sclateri deserves full specific status. (Hill, 1953; Kingdon, 1980; Nowak, 1999)


Cercopithecus sclateri occurs in moist tropical forests and swampy floodplain forests. These are low elevation habitats along the coast of Nigeria. Although this species' natural habitat is probably secondary growth and primary forest, it seems to be surviving in some extremely degraded habitats. An important habitat for this species is Igbo villages and their sacred tree groves, which are mostly surrounded by non-native tree plantations and agricultural areas. In one town, Lagwa (Imo state), all the patches of forest which the monkeys formerly inhabited have been cut down, leaving the animals to inhabit villages, where they steal food from gardens and farms. (Oates and Anadu, 1987; Oates, et al., 1992; Stewart, 1996)

Cercopithecus sclateri is a member of the Cercopithecus (cephus) superspecies group. Members of this group occur in primary rainforest like most of the other species of guenons, but also occur in secondary forests more often than other guenon species. In addition, the closely related species in this group seem to prefer the lower levels of the canopy and sometimes come to the ground. (Fleagle, 1999; Nowak, 1999)

Physical Description

Sclater's guenon, like all guenons, is a very colorful monkey with a complicated facial pattern. The body is overall a dusky gray color with some greenish tinge on the back. The tail is very long (about one-half the total length) and is reddish colored on the ventral proximal part, gradually becoming white distally and ending in a black tip. The muzzle is brownish pink with a creamy white nose spot (above the nostrils on the bridge of the nose). The face is adorned with three major hair patches. The crown and cheek patches are yellow mixed with black. In addition, there is a large white throat patch extending almost to the ears. The ears have prominent white tufts. Finally, black temporal bars extend past the ears and meet at the back of the head. (Hill, 1953; Kingdon, 1980; Nowak, 1999; Oates, et al., 1992)

Cercopithecus sclateri, along with the other members of their superspecies group, is among the smaller guenons. The species is somewhat sexually dimorphic. Females weigh about 2.5 kg whereas males weigh about 4.0 kg. All guenons, including C. sclateri, have sexually dimorphic canines. In addition, they have longer hindlimbs than forelimbs. Finally, a distinguishing characteristic that helps to separate all guenons from the colobus monkeys is the presence of cheek patches. (Fleagle, 1999; Hill, 1953; Nowak, 1999)

  • Sexual Dimorphism
  • male larger
  • Range mass
    2.5 to 4.0 kg
    5.51 to 8.81 lb
  • Range length
    80 to 120 cm
    31.50 to 47.24 in


There is little information available on reproduction in C. sclateri. However, members of the genus are typically polygynous, and it is reasonable to assume that C. sclateri is as well. The mating system of their superspecies group differs from other guenons in the decreased importance of single male groups. Instead, females seem to make up the core group and they often travel together without a male. Female independence seems to be very important, as females defend territories from other groups. Males in the C. (cephus) group, including C. sclateri probably practice opportunism with respect to copulation with females rather than guarding groups of females as do other members of the genus. Males signal to females prior to mounting them. They do this with head weaving movements which have been hypothesized to be an important courtship ritual used to reassure females with whom a male wants to mate. In addition, these head weaving movements may have contributed to the radiation of the complex facial patterns of C. sclateri and other species in the C. (cephus) group. (Fleagle, 1999; Kingdon, 1980)

Very little information is available on the reproduction of C. sclateri because the species was recently discovered. The first observations of these animals in the wild occurred in 1988. This delayed discovery may be due in part to the fact that these monkeys inhabit an area of Nigeria that has long been avoided by biologists and conservationists. In this part of Nigeria, there is a high human population, and a lack of natural areas in which to study animals. (Oates and Anadu, 1989; Oates, et al., 1992)

Generally, within the genus Cercopithecus, mating season corresponds to the time of highest food availability. For many species this occurs in July, August, and September, however, rainforest species, potentially including C. sclateri, exhibit more flexibility in this regard. Gestation is around 6 months with birth occurring during the months of December, January, or February. Young weigh approximately 400 g at birth, and cling to the mother's ventrum. The period of nursing is not known for this species, but like most Cercopithecines, it is probably complete by about 9 months of age. Females produce their first young at about 5 to 6 years of age. (Fleagle, 1999; Nowak, 1999; Oates, et al., 1992)

  • Breeding interval
    Intervals one to five years reported for species of Cercopithecus.
  • Breeding season
    No information reported for C. sclateri. The breeding season peaks for most species of guenons in the months of July, August and September.
  • Range number of offspring
    1 to 2
  • Average gestation period
    5 months
  • Range age at sexual or reproductive maturity (female)
    5 to 7 years

Little is known about parental investment in C. sclateri. The species is poorly studied, but probably resembles other Cercopithecine monkeys. A young guenon rides on its mother's ventrum, clinging to her fur and entwining its tail with hers. As in most Cercopithecines, parental care is probably provided primarily by the mother. She nurses, carries, and grooms her offspring. Infants are generally dependent upon their mother for all forms of care. Cercopithecine young typically remain with their mother for some time after weaning. It is not uncommmon for rank of mothers to affect the dominance standing of their offspring. The role of males in the parental care of this species has not been reported. (Nowak, 1999)

  • Parental Investment
  • no parental involvement
  • altricial
  • female parental care
  • pre-fertilization
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
  • extended period of juvenile learning


Cercopithecus sclateri is not known from captivity (one animal at Port Harcourt Zoo, Nigeria) and no ages from the wild have been reported. Other closely related guenons can live to around 20 years of age. (Johnson, 2002; Nowak, 1999)


There are no behavioral studies of C. sclateri in the wild. However, in the members of the superspecies C. (cephus), group structure is less strict than in other members of Cercopithecus. Specifically, C. (cephus) does not have a single dominant male; rather, groups can be multi-male, composed of family members, or all female. (Kingdon, 1980)

Locomotion in the genus Cercopithecus is also poorly studied. Most guenons are quadrupedal and leap 10 percent of the time. It is known that their positional behavior is related to diet. For instance, climbing is negatively correlated to fruit in the diet. Species that eat larger numbers of insects use more transitional postures than other species. Guenons use their tails for balance and usually sleep in trees. (McGraw, 2002; Nowak, 1999)

Cercopithecus sclateri is sympatric with several other species of primates including Perodicticus potto, Arctocebus calabarensis, Cercocebus torquatus, Cercopithecus mona, and Cercopithecus nicticans. The closely related Cercopithecus cephus forms associations with C. nicticans in Gabon where they partition resources based on food type and preferred canopy feeding level. Since the C. (cephus) subgroup is thought to fill the same ecological niche, it is probable that C. sclateri forms such associations with other primates in its range. (Fleagle, 1999; Tooze, 1995)

Home Range

Little home range information is available for C. sclateri. However, closely related species have smaller home ranges than other members of the genus. The closely related C. ascanius used a 15 ha home range with a 5 ha core area, but this species is known to have home ranges up to 130 ha. (Nowak, 1999)

Communication and Perception

Cercopithecus sclateri, like the other members of its superspecies group Cercopithecus (cephus), has a striking facial pattern that is hypothesized to be used in communication relating to reproduction. Specifically, the cheek patches and nose may be important in signalling. This pattern, in conjunction with very fast and complex head weaving, may serve important roles in maintaining relationships with other members of a group. Sexual selection may play a role in the evolution of facial pattern in this species. The highly colored tail is probably also used to communicate with conspecifics. (Kingdon, 1980)

Within the genus Cercopithecus, 22 different vocalizations have been described. These include noises to maintain group cohesion, warning signals, and loud noises emitted by males (Nowak, 1999)

Tactile communication is important in all primates. Grooming behaviors typically indicate close relationships between individuals. Mothers communicate with their young through touching, as do mates. Physical aggression often occurs, especially between rival males. (Nowak, 1999)

Food Habits

Cercopithecus sclateri, like most small guenons, is probably predominantly a frugivore. Other important components of guenon diets include insects, flowers and leaves. They are omnivorous and because they inhabitat some villages and towns with little or no forest cover, they raid gardens and farms for food. The only specific reference to a species which is eaten by these guenons is the red silk cotton tree, Bombax buonopozense. (Butynski, 2002a; Fleagle, 1999; Nowak, 1999; Oates, et al., 1992)

  • Animal Foods
  • birds
  • reptiles
  • eggs
  • insects
  • Plant Foods
  • leaves
  • roots and tubers
  • seeds, grains, and nuts
  • fruit
  • nectar
  • flowers


Cercopithecus sclateri may become wary of humans in response to hunting pressure. Other specific information on the predators of these guenons is not available. It is likely, however, that they do fall prey to large snakes, raptors, and mammalian carnivores. (Oates, et al., 1992)

Ecosystem Roles

The most important role of C. sclateri is probably as a seed disperser. Their cheek pouches may facilitate the spread of seeds. It is unlikely that this species, because of its rarity, is important as a prey item. (Kingdon, 1980; Nowak, 1999)

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Cercopithecus sclateri is hunted for food in virtually all of its range, although hunting is not an important activity in this area because of the relative lack of game. In addition, the possibility that ecotourism could become an important part of the conservation plan for this species has been proposed due to its proximity to currently visited areas in Nigeria. (Baker and Tooze, 2003; Butynski, 2002b; Oates and Anadu, 1987; Oates and Anadu, 1989; Oates, et al., 1992; Oates, 1996; Tooze, 1995)

Economic Importance for Humans: Negative

Cercopithicus sclateri is known to raid gardens and farms for food. Some villagers consider it a nuisance. (Oates, et al., 1992)

  • Negative Impacts
  • crop pest

Conservation Status

Sclater's guenons are one of the most endangered primates in Africa. The combination of an extremely small range in a very populous part of Nigeria have pushed this species to the brink of extinction. The area of Nigeria in which these guenons are found has one of the densest rural populations in all of Africa. The vast majority of the land area has been converted to agricultural use and non-native plantations. Two populations of Sclater's guenons are known to occur in forest reserves, although these reserves provide little protection. A conservation project was started in the Stubbs Creek Forest Preserve in Akwa Ibom State, although it has largely failed to produce results. (Butynski, 2002b; Nowak, 1999; Oates and Anadu, 1989; Oates, et al., 1992; Oates, 1996)

Major threats to C. sclateri include habitat destruction and hunting. These, in turn, are driven by the rapidly expanding human populations. In addition, the area in which C. sclateri occurs is located over oil fields, and major oil development is occurring on the Niger delta. Recent surveys, however, are discovering more populations of Sclater's guenons. All of them occur in relatively small, isolated patches of forests. Some small hope is found in the fact that this species is associated with shrines and sacred groves of trees in some villages. The monkeys are protected at these sites because of a taboo associated with killing or eating the monkeys. In some cases, they are thought of as protectors of the sacred sites. However, the younger generation may be losing some of these inhibitions to killing these monkeys. (Baker and Tooze, 2003; Butynski, 2002b; Oates and Anadu, 1989; Oates, et al., 1992; Tooze, 1995)


Nancy Shefferly (editor), Animal Diversity Web.

Jason Law (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.



living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map


uses sound to communicate


living in landscapes dominated by human agriculture.


young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.


Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


active at dawn and dusk

  1. active during the day, 2. lasting for one day.

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females


union of egg and spermatozoan


A substance that provides both nutrients and energy to a living thing.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


an animal that mainly eats fruit


An animal that eats mainly plants or parts of plants.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


having more than one female as a mate at one time


rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

seasonal breeding

breeding is confined to a particular season


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.


uses touch to communicate


Living on the ground.


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


uses sight to communicate


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.


Baker, L., Z. Tooze. 2003. Status of the Sclater's Guenon (Cercopithecus sclateri) in southeastern Nigeria. American Journal of Primatology, 60(Suppl 1): 88-89.

Butynski, T. 2002. Conservation of the guenons: An overview of status, threats, and recommendations. Pp. 411-415 in Glenn, Cords, eds. The guenons: Diversity and adaptation in African Monkeys. New York: Kluwer Academic.

Butynski, T. 2002. The guenons: An overview of diversity and taxonomy. Pp. 3-13 in Glenn, Cords, eds. The guenons: Diversity and adaptation in African Monkeys. New York: Kluwer Academic.

Fleagle, J. 1999. Primate adaptation and evolution. New York: Academic Press.

Groves, C. 2000. The phylogeny of the Cercopithecoidea. Pp. 92-95 in P Whitehead, C Jolly, eds. Old World Monkeys. London: Cambridge University Press.

Hill, W. 1953. Primates: Comparative Anatomy and Taxonomy VI, Catarrhini, Cercopithecoidea. New York: Interscience.

Johnson, D. 2002. "Life spans of non-human primates" (On-line). Primate Info Net. Accessed August 25, 2004 at http://pin.primate.wisc.edu/aboutp/phys/lifespan.html.

Kingdon, J. 1980. The role of visual signals and face patterns in African forest monkeys (guenons) of the genus Cercopithecus. Transactions of the Zoological Society of London, 35: 425-475.

McGraw, W. 2002. Diversity of guenon positional behavior. Pp. 125 in Glenn, Cords, eds. The guenons: Diversity and adaptation in African Monkeys. New York: Kluwer Academic.

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

Oates, J. 1996. African Primates: Status Survey and Conservation Action Plan. Gland, Switzerland: International Union for Conservation of Nature.

Oates, J., P. Anadu. 1989. Folia Primatologica, 52(1-2): 38-42.

Oates, J., P. Anadu. 1987. Sclater's guenon: First field observation [Abstract]. International Journal of Primatology, 8(5): 555.

Oates, J., P. Anadu, E. Gadsby, J. Werre. 1992. Sclater's guenon: A rare Nigerian monkey threatened by deforestation. National Geographic Research and Exploration, 8(4): 476-491.

Stewart, C. 1996. Africa's Vanishing Wildlife. Washington, D.C.: Smithsonian Institution Press.

Tooze, Z. 1995. Update on Sclater's guenon, Cercopithecus sclateri, in southern Nigeria. African Primates, 1(2): 38-42.