Primates Id code: amd050Cercopithecidae Cercopithecus pogonias Bennett, 1833 (Eng) Crowned guenon (Fre) Guenon couronné Taxonomic notes Three subspecies have been described (Lernould, 1988). IUCN threat category Not listed as a species, but Vulnerable (VU: criteria A2c) as C. p. pogonias (Fernando Po crowned monkey) in Cameroon and Equatorial Guinea. Available information Literature available on the ecology of the species is quite limited, and only some aspects of the species’ ecology have been studied. Information on its feeding habits reported by several authors (Gartlan & Struhsaker, 1979; Gautier-Hion, 1988; Gautier-Hion et al., 1980; Gautier-Hion et al., 1983; Mitani, 1991); most of the authors mentioned analyse the niche separation and coexistence with other primate species. Behavioural aspects of the ecology of the species are discussed in Gautier-Hion & Gautier (1986) and Struhsaker (1979). Notes on its habitat use on Bioko Island are reported by Gonzalez-Kirchner (1996); population number and species density were also investigated on Bioko Island (Arihà) (Maté & Colell, 1995). Data on the species’ distribution are available for part of former Zaire (Colyn, 1987; 1988), Bioko Island (Butynski & Koster, 1994), Gabon (Blom et al., 1992), part of Congo and Cameroon (Mitani, 1990; Usongo & Fimbel, 1995), and Angola (Feiler, 1990). Most of the authors mentioned above also give some information on the ecology of the species, particularly its habitat. Overall distribution is discussed in Lernould (1988) and Oates (1988). General information on the ecology of the species is found in Bourlière (1985), Kingdon (1997), and Stuart & Stuart (1997). Its status is discussed in Oates (1996). Known extent of occurrence 
This guenon occurs in south-east Nigeria, Cameroon, C.A:R., Bioko and Rio Muni (Eq. Guinea), Gabon, west former Zaire, Congo (Oates, 1996), being limited possibly by the Cross River to the west, by the Itimbiri River to the east and by the Zaire River to the south of its range (Kingdon, 1997). A first rough map was drawn by joining its distribution range on Bioko Island taken from Butynski & Koster (1994) with the mainland one taken from Lernould (1988); the extent of occurrence was then revised on the basis of the river network (Fig. 2.3.19.a). Categorical-discrete (CD) distribution model This species is found mainly in primary lowland tropical forest; but also in secondary forest and gallery forest extending into savanna areas (Gonzalez-Kirchner, 1996; Kingdon, 1997). Based on these environmental preferences, the following scores were assigned (Fig. 2.3.19.b) (Tab. 2.3.19.a):
Tab 2.3.19.a: Cumulative size (km2) of areas pertaining to each environmental suitability class within the Extent of Occurrence.
Tab 2.3.19.b: Area of Occupancy fragmentation indexes. Probabilistic-continuous (PC) distribution model The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.3.19.c. Validation
Tab 2.3.19.c: Categorical-discrete (CD) distribution model validation parameters. Comments and conservation issues The known EO of this species is large but appears to include wide zones of limited suitability, as in central-southern Congo, central C.A.R. and western Cameroon. The Index of Accordance (45.71%) suggests some caution in interpreting the result of the CD model. The PC model, not considering the close association to water bodies in secondary vegetation types, smooths the distribution of suitability classes. Most of the EO is, however, of sufficient suitability and also relatively continuous (NP and LPI). The AWMSI shows that the shape of the most important patches is highly indented and irregular, a possible indication of high interspersion of areas of different suitability classes. About 4% of the total AO is included in existing protected areas.
Tab 2.3.19.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. 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. 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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