Cercopithecus sclateri
Sclater's guenon

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)

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)

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)

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)

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, 2002b; Fleagle, 1999; Nowak, 1999; Oates et al., 1992)

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)

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)

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

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, 2002a; Oates and Anadu, 1987; Oates and Anadu, 1989; Oates et al., 1992; Oates, 1996; Tooze, 1995)

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, 2002a; 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, 2002a; Oates and Anadu, 1989; Oates et al., 1992; Tooze, 1995)