Primates Id code: amd303Cercopithecidae Cercocebus agilis Milne-Edwards, 1886 (Eng) Agile or golden-bellied mangabey(Fre) Cercocèbe agile Taxonomic notes In accordance with Wilson & Reeder (1993) this species is considered distinct from C. galeritus and includes the subspecies: C. a. chrysogaster (Golden-bellied mangabey) in former Zaire and C. a. sanjei (Sanjei crested mangabey) in Tanzania. Baillie & Groombridge (1996) and Oates (1996) still maintain the original classification. IUCN threat category Lower Risk, near threatened (LR: nt) as C. g. agilis, but Endangered (EN: criteria B1+2c) as C. g. sanjei and Data Deficient (DD) as C. g. chrysogaster. Available information The species’ ecology has been poorly studied. Notes on its ecology in north-east Gabon are found in Quris (1975). Some information on the habitat in which it occurs is reported in Bourlière (1985), Colyn (1988) and Homewood & Rodgers (1981), while Gautier-Hion & Gautier (1986) focus on behavioural aspects of the species’ ecology. The species’ presence has been thoroughly surveyed in parts of former Zaire (Colyn, 1988), Congo and Cameroon (Mitani, 1990). Status and threats are discussed in Lee et al. (1988); the authors also give some information on the species’ ecology. General information on the biology of the species is found in Kingdon (1997). Known extent of occurrence 
This species ranges in Eq. Guinea, Cameroon, north-east Gabon, south C.A.R., north Congo Republic and former Zaire (Wilson & Reeder, 1993). The newly discovered sanjei form is endemic to a small area around the Uzungwa Mts. in Tanzania (Lee et al., 1988). The southern limits have been identified as the watershed between the Aruwimi and Lindi Rivers (Colyn, 1988). Fig. 2.3.2.a was obtained from Groves (1978) and revised on the basis of both the river network and the new map in Kingdon (1997). Categorical-discrete (CD) distribution model This species is associated to swamp, riparian and seasonally flooded forests (Bourlière, 1985; Kingdon, 1997). Based on these environmental preferences, the following scores were assigned (Fig. 2.3.2.b) (Tab. 2.3.2.a):
Tab 2.3.2.a: Cumulative size (km2) of areas pertaining to each environmental suitability class within the Extent of Occurrence.
Tab 2.3.2.b: Area of Occupancy fragmentation indexes. Probabilistic-continuous (PC) distribution model The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.3.2.c. Validation
Tab 2.3.2.c: Categorical-discrete (CD) distribution model validation parameters. Comments and conservation issues The known EO of this species is divided into three separate portions, inhabited by different subspecies. According to the CD model, which is amply supported by the validation parameters (Index of Accordance = 70%), its AO in central Africa, on both sides of the Zaire River, is largely suitable and interconnected, as shown by the NP and LPI, while the quite separate portion in Tanzania is apparently mostly unsuitable, confirming the endangered status of the sanjei form. The PC model confirms this general pattern, though indicating better suitability values in the southern portion of the main range. Moreover, it clearly shows low suitability peaks matching major cities. About 7% of the AO is included in existing protected areas; the Uzungwa National Park appears essential for the survival of the Sanjei crested mangabey, while further research is needed to clarify the distribution, taxonomy and conservation status of the species in the central forest block.
Tab 2.3.2.d: Percent of environmental suitability classes within EO (as obtained from the categorical-discrete distribution model) inside and outside the protected areas. References Baillie J., Groombridge B. (Eds) (1996). 1996 IUCN Red List of Threatened Animals. IUCN Species Survival Commission. Bourlière F. (1985). Primate communities: their structure and role in tropical ecosystems. Int J. Primatol.: 6, 1-26. Colyn M.M. (1988). Distribution of guenons in the Zaire-Lualaba-Lomani river system. In: Gautier-Hion A., Bourlière F., Gautier J., Kingdon J. (Eds). A Primate Radiation: Evolutionary Biology of the African Guenons. Cambridge University Press, New York: pp 104-124. Gautier-Hion A., Gautier J. (1986). Sexual dimorphism, social units and ecology among sympatric forest guenons. Symposia of the Society for the Study of Human Biology: 24, 61-77. Groves C.P. (1978). Phylogenetic and population systematics of the Mangabeys (Primates: Cercopithecoidea). Primates: 19, 1-34. Homewood K.M., Rodgers W.A. (1981). A previously undescribed Mangabey from southern Tanzania. Int J. Primatol.: 2, 47-55. Kingdon J. (1997). The Kingdon field guide to African Mammals. Academic Press, London and New York: Natural World. Lee P.C., Thornback J., Bennet E.L. (1988). Threatened Primates of Africa. IUCN, Gland - Switzerland and Cambridge, UK. Mitani M. (1990). A note on the present situation of the primates fauna found from South-eastern Cameroon to Northern Congo. Primates: 31(4), 625-634. Oates J.F. (1996). African Primates Status Survey and Conservation Action plan. IUCN/SSC Primate Specialist Group. Quris R. (1975). Ecologie et organisation sociale de Cercocebus galeritus agilis dans le Nord-Est du Gabon. Revue de Ecologie (La Terre et la Vie): 3, 337-398. Wilson D.E., Reeder D.M. (Eds) (1993). Mammal Species of the World: A Taxonomic and Geographic Reference. Second edition. Smithsonian Institution Press, Washington D.C.
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