Primates Id code: amd049Cercopithecidae Cercopithecus nictitans (Linnaeus, 1766) (Eng) Spot-nosed guenon(Fre) Hocheur Taxonomic notes According to Lernould (1988), three subspecies are recognized: C. n. nictitans, C. n. martini, C. n. stampfilii. IUCN threat category Not listed. Available information Diet and interspecific relationships with other primate species have been quite intensely studied, while there is a lack of information on other aspects of the species' ecology, such as habitat use and requirements and spacing patterns. Its feeding habits were investigated in Gabon by Gautier-Hion (1988), Gautier-Hion et al. (1980) and Gautier-Hion et al. (1983); some information on the species' diet is also available from Mitani (1991), who focused on the niche overlap among coexisting primates in the Campo Animal Reserve (southwestern Cameroon). Interspecific relationships and niche separation among coexisting primate species were also investigated by Gartlan & Struhsaker (1979). Behavioural aspects of the ecology of the species are discussed in Galat & Galat-Luong (1985), Gautier-Hion & Gautier (1986), and Struhsaker (1979). Some information on its habitat use in Bioko Island is found in Gonzalez-Kirchner (1996). Information on the species' density and population number in Arihà (Bioko Island) is supplied by Maté & Colell (1995). Data on the species' distribution are available for part of Cameroon and Congo (Mitani, 1990; Usongo & Fimbel, 1995), Lualaba-Lomani District (former Zaire) (Colyn, 1987, 1988), Gabon (Blom et al., 1992), Bioko Island (Butynski & Koster, 1994), and Angola (Feiler, 1990); the authors quoted above also give some information on the habitat in which the species is found. The overall species distribution is analysed in Lernould (1988) and Jacobsen & Hamel (1994). General information on the species' ecology is found in Bourlière (1985), Kingdon (1997) and Stuart & Stuart (1997). Known extent of occurrence  The geographic distribution (Fig. 2.3.17.a) was obtained from Lernould (1988) for continental Africa and from Butynski & Koster (1994) for Bioko. It was then adjusted with the river network to match the exact boundaries (i.e. north of the Zaire River). This species' range stretches from Nigeria to northwest former Zaire, C.A.R., Rio Muni and Bioko Is. in Eq. Guinea, Gabon and Congo. A separate population occurs in Liberia, Ivory Coast and SE Guinea (Oates, 1996). Categorical-discrete (CD) distribution model This species occurs in lowland, montane, primary and secondary forests, and in forests along rivers (Lernould, 1988; Oates, 1988; Kingdon, 1997). Based on these environmental preferences, the following scores were assigned (Fig. 2.3.17.b) (Tab. 2.3.17.a):
Tab 2.3.17.a: Cumulative size (km2) of areas pertaining to each environmental suitability class within the Extent of Occurrence.
Tab 2.3.17.b: Area of Occupancy fragmentation indexes. Probabilistic-continuous (PC) distribution model The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.3.17.c. Validation
Tab 2.3.17.c: Categorical-discrete (CD) distribution model validation parameters. Comments and conservation issues The known EO includes areas where the suitability appears to be quite low, as in central Nigeria, central-northern C.A.R. and central Congo. However, about 60% of the large EO is classified as suitable, and this figure is well supported by the validation parameters (Index of Accordance 75.34%). These areas appear very fragmented (NP, MPS and PSSD) with the exception of a major suitable patch that covers more than 50% of the total suitable areas. Fragmentation is greatly reduced when the moderately suitable areas are also considered, but both of these types of areas and the unsuitable ones are highly interspersed, as shown by the high values of the AWMSI. Only 5.5% of the total AO is included in existing protected areas.
Tab 2.3.17.d: Percent of environmental suitability classes within EO (as obtained from the categorical-discrete distribution model) inside and outside the protected areas. References Blom A., Alers M.P.T., Feistner A.T.C., Barnes R.F.W., Barnes K.L. (1992). Primates in Gabon - current status and distribution. Oryx: 26(4), 223-234. Bourlière F. (1985). Primate communities: their structure and role in tropical ecosystems. Int J. Primatol.: 6, 1-26. Butynski T.M., Koster S.H. (1994). Distribution and conservation status of primates in Bioko Island, Equatorial Guinea. Biodiversity Conserv: 3(9), 893-909. Colyn M.M. (1987). Les primates de la foret ombrophile de la Cuvette du Zaire: interprétations zoogéographique des modèles de distribution. Rev. Zool. Africaine: 101, 183-196. 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. Feiler A. (1990). Distribution of mammals in Angola and notes on biogeography. Vertebrates in the tropics (Peters, G & R Hutter, eds). Museum Alexander Koenig, Bonn.: 221-236. Galat G., Galat-Luong A. (1985). La communauté de Primates diurnes de la foret de Tai, Côte d'Ivoire. Revue de Ecologie (La Terre et la Vie): 40, 7-32. Gartlan J.S., Struhsaker T.T. (1979). Polyspecific associations and niche separation of rain-forest anthropoids in Cameroon, West Africa. In: Sussman R.W. (Ed.). Primate Ecology. Problem-oriented field studies. Wiley, Chichester & New York: pp 155-164. Gautier-Hion A. (1988). The diet and dietary habits of forest guenon. 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 257-283. Gautier-Hion A., Emmons L.H., Dubost G. (1980). A comparison of the diets of three major groups of primary consumers of Gabon (primates, squirrels and ruminants). Oecologia (Berlin): 45, 182-189. 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. Gautier-Hion A., Quris R., Gautier J. (1983). Monospecific vs. polyspecific life: a comparative study of foraging and antipredatory tactics in a community of Cercopithecus monkeys. Behav. Ecol. Sociobiol.: 12, 325-335. Gonzalez-Kirchner J.P. (1996). Notes on habitat use by the Russet-eared guenon (Cercopithecus erythrotis Waterhouse 1838) on Bioko Island, Equatorial Guinea. Tropical Zoology: 9, 297-304. Jacobsen L., Hamel R. (Eds) (1994). International directory of Primatology. 2nd. Wisconsin Regional Primate Center, Madison USA. Kingdon J. (1997). The Kingdon field guide to African Mammals. Academic Press, London and New York: Natural World. Lernould J. (1988). Classification and geographical distribution of guenons: a review. 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 54-78. Maté C., Colell M. (1995). Relative abundance of forest Cercopithecines in Arihà, Bioko Island, Republic of Equatorial Guinea. Folia Primatol.: 64, 49-54. 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. Mitani M. (1991). Niche overlap and polyspecific association among sympatric Cercopithecids in the Campo Animal Reserve, Southwestern Cameroon. Primates: 32(2), 137-151. Oates J.F. (1988). The distribution of Cercopithecus monkeys in West african forests. 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 79-103. Oates J.F. (1996). African Primates Status Survey and Conservation Action plan. IUCN/SSC Primate Specialist Group. Struhsaker T.T. (1979). Correlates of ecology and social organisation among African cercopithecines. In: Sussman R.W. (Ed.). Primate Ecology. Problem-oriented field studies. Wiley, Chichester & New York: chap. 20: 391-404. Stuart C., Stuart T. (1997). Field guide to the larger mammals of Africa. Struik Publishers. Usongo L., Fimbel C. (1995). Preliminary survey of arboreal primates in Lobeke forest Reserve, south-east Cameroon. African Primates IUCN/SSC Primate Specialist Group: 1 (2), 46-48.
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