Cercocebus agilis
(Cercocebus
a. agilis / C. galeritus agilis)
1886
C. agilis agilis by Milne-Edwards
1900
C. hagenbecki by Lydekker (who viewed a specimen
brought to
1914
C. fumosus by Matschie
1915
C. oberlaenderi by Lorenz
1993
C. agilis by
2006
C. agilis by IUCN/SSC Primate Specialist Group
Early 1900’s
Thought to be 4 subspecies throughout the range –
agilis, hagenbecki, fumosus and
oberlaenderi. Later deemed
insufficient differences to warrant separate subspecies distinction.
The English translation for the Latin "agilis" is "agile, nimble, active", hence
the common name.
Agile mangabeys were previously listed as a C. galeritus subspecies.
English translation for the Latin "galeritus" is "wearing a cap" (galerum = cap)
in reference to the hair whorl and crest on the head of the actual
galeritus subspecies like the
In French the common name is “cercocèbe agile”.
Information From the Wild
Distribution from SE Cameroon, NE Gabon, SW Central African Republic (CAR), N Congo (Brazzaville) to E Democratic Republic of Congo (DRC, formerly Zaire). Early reports in the late 1960’s of Agile mangabeys ranging into Equatorial Guinea are unverified at this time (Shah, 2003). In Cameroon, the range abuts with the range of red-capped mangabeys (Cercocebus torquatus). Semi-terrestrial "form" of mangabey with marked sexual dimorphism. Shah (2003) reports that adult females are approximately 60% the body weight of adult males.
Found in seasonally or intermittently flooded areas of primary forests near rivers or lakes (Quris, 1973). Has also been observed in terra firme forest. This species seems to prefer the lower strata of vegetation. Living at this level in a flooded forest provides C. agilis with double protection, firstly against ground predators which do not penetrate the flooded forest except with difficulty and secondly against birds of prey because of the dense undergrowth (Quris, 1973). They spend between 12 – 22% of their time on the ground (Quris, 1975; Shah, 2003). Shah found that adult males are significantly more terrestrial than females. Although omnivorous, C. agilis shows a marked preference for fruit (ripe, unripe or even over-ripe). They also eat old seeds and nuts, which persist on the forest floor for months, or which they find by digging up or sifting through elephant dung (Ekondzo and Gautier-Hion, 1998). Their broad molars, thickened enamel and powerful jaws enable mangabeys to open tough pods and other fruit which most monkeys cannot access.
Shoots and terminal tips of herbs and other grasses are an important food source after the preferred fruits. Other food items include roots, mushrooms, insects, invertebrates, seedlings, bird’s eggs and vertebrate prey like rodents (Shah, 2003: Quris, 1975; Kambale Sambili, 1998). When food items are scarce, mangabeys have to travel further, spend more time foraging on the ground and spend a greater percentage of their day searching for food. Group composition is single-male or multi-male troops of 8 to 18 individuals (Quris, 1973). At one study site in NE Gabon, home range was 1.98 km2 with 6.7 to 12.5 animals per km2 (Quris, 1975). Thomas (1991) estimated 0.25 groups/ km2 or around two individuals per km2 in the Ituri forest in DRC. In the Ndoki forest of southern CAR / northern Congo (Brazzaville), densities in terra firme forests were estimated to be 6.9 individuals/km2 (Shah, 2003). In southwestern CAR and southeastern Cameroon, larger groups of up to 50 individuals have been observed near water habitats or forest clearings. It is unclear if this means that there is a greater population density in these habitats or that these are temporary congregations (Usongo and Fimbel, 1995; Shah, 2003).
The adult male of a group functions not only as leader, but also as a warden and defender. These males emit calls of strong intensity, which appear only after sexual maturity. These calls can be heard up to 1000 m (3500 ft) away and may play a part in regulating inter- and intra-group distances. This call is specific to this subspecies. Other vocalizations help maintain cohesion within the group and also transmit vital information such as predator alarms, etc. While the calls of C. agilis fulfill the same functions as those of other forest monkeys, the call structure and releasing mechanism more resembles those of baboons and macaques (Quris, 1973). The vocal repertoire of C. agilis relates this subspecies to both the forest and the more open environment cercopithecines. This two-fold relationship is also paralleled in anatomical, ecological and behavioral traits (Quris, 1973).
Description
The hair coloration over the body can be described as "agouti" (different colored bands down the length of the hair shaft). This hair has a short gray base, along blackish stem, an unclear smoky green-yellow to gray-white band, a black band, a yellow-orange band, and usually a black tip. The bands give the appearance of an overall brownish-gray with the pelage darkest on the back. The black tip is invariable on the crown. The tail has no agouti bands except at the base; blackish above fading to olive-brown and light below. Underside is a washed out fawn, often with a white or yellow tinge; this color extending to the chin and under the tail (Groves, 1978).
The skin of the hands and feet, face and ears are black (Shah, 2003). There is a slight "whorl" above the forehead with some hair lying forward over the brow from the whorl. The light hair bases, swept back from the cheeks, give a white border to the face. Upper eyelids are flesh-colored (Groves, 1978). The tails of some individuals have a whitish terminal tuft (Shah, 2003).Infants are born with a pale pink facial skin color that darkens over time (Shah, 2003). There might be some regional pelage differences with animals in the north being of a lighter coloration (Groves, 1978). Shah (2003) reports that the light and dark color morphs co-occur throughout the range of the species. Individuals in the western portion of the range may be larger in body size.
In Captivity - North American Region
Only 7 individuals in this region from 1954 to 1967. All of the 4-recorded captive births (no twins) were from one pair and each infant lived less than one week.There are currently C. a. agilis in captivity in Europe (Field, pers. comm.).