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Primates
Id code: amd311Cercopithecidae
Colobus satanas
Waterhouse, 1838
(Eng) Black colobus
(Fre) Colobe noir
Taxonomic notes
The number of taxonomically distinct populations that can be identified within the genus Colobus and their phylogenetic relationships are still under debate (Oates & Trocco, 1983). Most authors, however, agree in considering C. satanas a fully distinct species (Wilson & Reeder, 1993; Oates & Trocco, 1983; Oates, 1996)
IUCN threat category
Vulnerable (VU: criteria A1c).
Available information
Little is known on the ecology of the black colobus, and no comprehensive studies have been carried out. Ranging behaviour, feeding habits and activity rhythms were investigated in a coastal area in Cameroon (McKey, 1978; McKey & Waterman, 1982; McKey et al., 1981). Data on its feeding habits are also available for central Gabon (Harrison, 1984). Updated data on its status and distribution are available for its whole range of distribution, except for part of Congo (Oates, 1996). Coexistence with humans and conservation issues are discussed in Mittermeier (1986) and Oates (1977). Status and distribution were recently investigated on Bioko Island (Butynsky & Koster, 1994), Gabon (Blom et al., 1992), and part of Cameroon and Congo (Carpaneto, 1995; Mitani, 1990). General information on the species' ecology is found in Kingdon (1997), Rahm (1970) and Stuart & Stuart (1997). An overall discussion on its threats, status and distribution is found in Oates (1996).
Known extent of occurrence
This species is restricted to rain forest in Cameroon (south of the Sanaga River), Gabon, parts of Congo and Eq. Guinea, both mainland Rio Muni and Bioko Island (Oates, 1996). The distribution map presented in Fig. 2.3.36.a was derived from the overlapping of maps in two reliable and recent publications (Butynski & Koster, 1994; Oates, 1996).
Categorical-discrete (CD) distribution model
This species needs high canopy forest; it has been found in montane and swamp forests and may be unable to survive in secondary forest. It appears more sensitive to habitat disturbance than other members of black and white colobus (Eisenberg et al., 1979; Lee et al., 1988; Oates, 1996).
Based on these environmental preferences, the following scores were assigned (Fig. 2.3.36.b) (Tab. 2.3.36.a):
|
Score |
|
|
1 |
Primary and seasonal tropical forests. |
|
2 |
Primary forest mosaics, secondary forest. |
|
3 |
Secondary forest mosaics, degraded forest, savannas and croplands. |
|
suitable |
moderately suitable |
unsuitable |
Total |
||||
|
km2 |
% |
km2 |
% |
km2 |
% |
km2 |
% |
|
243 950 |
70 |
19 060 |
5 |
84 624 |
24 |
347 634 |
100 |
Tab 2.3.36.a: Cumulative size (km2) of areas pertaining to each environmental suitability class within the Extent of Occurrence.
|
Number Patches (NP) |
Mean Patch Size (MPS) km2 |
Patch Size SD (PSSD) km2 |
Largest Patch Index (LPI) % |
Mean Shape Index (MSI) |
Area-Weighted Mean Shape Index (AWMSI) |
|
|
suitable |
117 |
2 090 |
21 360 |
88.37 |
1.35 |
12.76 |
|
moderately suitable |
249 |
73 |
174 |
0.65 |
1.16 |
1.94 |
|
Total AO |
96 |
2 736 |
25 534 |
95.78 |
1.37 |
13.18 |
Tab 2.3.36.b: Area of Occupancy fragmentation indexes.
Probabilistic-continuous (PC) distribution model
The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.3.36.c.
Validation
|
% of EO in sample areas |
Number of valid plots |
Index of Accordance (%) |
|
42.29 |
35 |
45.71 |
Tab 2.3.36.c: Categorical-discrete (CD) distribution model validation parameters.
Comments and conservation issues
About 70% of the known EO was found to be suitable and the less suitable areas are mostly found in the northern and western part of the range (see both models). The Index of Accordance of 45.71% reflects the scarce information available on the ecology of the species. The LPI of the suitable areas shows that one large patch ensures the availability of a continuous and rather compact range. Interspersion with less suitable areas is however evident from the CD model and confirmed by the AWMSI of the total AO. About 7% of the total AO is included in existing protected areas, but the species is classified as Vulnerable and probably requires a more extended protection system.
|
SUITABILITY CLASS |
inside |
outside |
Total |
|
suitable |
4.61 |
65.56 |
70.17 |
|
moderately suitable |
0.80 |
4.68 |
5.48 |
|
unsuitable |
1.60 |
22.74 |
24.34 |
|
Total |
7.02 |
92.98 |
100 |
Tab 2.3.36.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.
Butynski T.M., Koster S.H. (1994). Distribution and conservation status of primates in Bioko Island, Equatorial Guinea. Biodiversity Conserv: 3(9), 893-909.
Carpaneto G.M. (1995). Occurrence of black colobus Colobus satanas in northwestern Congo. African Primates: 1(2), 42-44.
Eisenberg J.F., Muckenhirn N., Rudran R. (1979). The relations between ecology and social structure in primates. [reprinted from Science (1972), 176: 863-874]. In: Sussman R.W. (Ed.). Primate Ecology. Problem-oriented field studies. Wiley, Chichester & New York. chap. 23: 455-484.
Harrison M.J.S. (1984). Feeding ecology of black colobus, Colobus satanas, in Central Gabon. In: Else J.G., Lee P.C. (Eds). Primate ecology and conservation. Selected Proceedings of the 10th Congress Int. Primatological Society, Nairobi, Kenya (July 1984). Cambridge University Press, Cambridge, U.K: chap. II.2, pp 31-38.
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.
McKey D. (1978). Soils, vegetation and seed-eating by black colobus monkeys. In: Montgomery G.G. (Ed.). The Ecology of Arboreal Folivores. Smithsonian Institution Press, Washington D.C.: pp 423-439.
McKey D., Waterman P.G. (1982). Ranging behaviour of a group of Black Colobus (Colobus satanas) in the Douala-Edea Reserve, Cameroon. Folia Primatol.: 39, 264-304.
McKey D.B., Gartlan J.S., Waterman P.G., Choo G.M. (1981). Food selection by black colobus monkeys (Colobus satanas) in relation to plant chemistry. Biol.J.Linn.Soc. 16: 115-146.
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.
Mittermeier R.A. (1986). A global overview of primate conservation. In: Else J.G., Lee P.C. (Eds). Primate ecology and conservation. Selected Proceedings of the 10th Congress Int. Primatological Society, Nairobi, Kenya (July 1984). Cambridge University Press, Cambridge, U.K: chap. VI.7, 325-341.
Oates J.F. (1977). The Guereza and Man: How man has affected the distribution and abundance of Colobus guereza and other Black Colobus Monkeys. In: Bourne G.H. (Ed.). Primate Conservation. Academic Press, London and New York.
Oates J.F. (1996). African Primates Status Survey and Conservation Action plan. IUCN/SSC Primate Specialist Group.
Oates J.F., Trocco T.F. (1983). Taxonomy and phlyogeny of black-and-white colobus monkeys: inferences from an analysis of loud call variation. Folia Primatol.: 40, 83-113.
Rahm U. (1970). Ecology, zoogeography and systematics of some African forest monkeys. In: Napier J.R., Napier P.H. (Eds). Old World Monkeys. Evolution, Systematics and Behavior. Academic Press, London and New York: pp 591-626.
Stuart C., Stuart T. (1997). Field guide to the larger mammals of Africa. Struik Publishers.
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.