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Primates
Id code: amd066Cercopithecidae
Cercopithecus erythrogaster
Gray, 1866
(Eng) Red-bellied or white-throated guenon
(Fre) Cercopithéque à ventre rouge
Taxonomic notes
No significant taxonomic notes.
IUCN threat category
Vulnerable (VU: criteria A1c).
Available information
Little is known on the ecology of the white-throated guenon. The main reference is Oates (1985), who gave a detailed account of what is known of the ecology of this species. Most of the information consists in observations conducted by the author. A rather detailed picture of habitat preferences is given; instead, diet, behaviour, population structure and density are very poorly known. Locations of collected specimens and overall geographic distribution are also reported by the author. Distribution and some notes on the habitat are also found in Lernould (1988) and Oates (1988). General information on the species’ ecology and distribution is provided in Kingdon (1997) and Stuart & Stuart (1997). Status, threats and distribution are discussed in Oates (1996). The species is included in the list of the most threatened African primate species (Lee et al., 1988).
Known extent of occurrence
This species is known only from Southwest Nigeria, where it is restricted to west of the Niger Delta, but it may extend east of the delta and reach Benin (and possibly Togo) in the west (Lernould, 1988). The distribution map was obtained from Oates (1996), adjusted to include locations from Oates (1985, 1988) and revised following the river network (Fig. 2.3.10.a).
Categorical-discrete (CD) distribution model
Restricted to primary and secondary lowland forests and their surroundings (Oates, 1996; Lee et al., 1988; Kingdon, 1997).
Based on these environmental preferences, the following scores were assigned (Fig. 2.3.10.b) (Tab. 2.3.10.a):
|
Score |
|
|
1 |
Forests. |
|
2 |
Forest mosaics. |
|
3 |
Savannas and croplands. |
|
suitable |
moderately suitable |
unsuitable |
Total |
||||
|
km2 |
% |
km2 |
% |
km2 |
% |
km2 |
% |
|
46 791 |
48 |
37 653 |
38 |
13 935 |
14 |
98 379 |
100 |
Tab 2.3.10.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 |
58 |
802 |
4 597 |
41.24 |
1.45 |
9.34 |
|
moderately suitable |
113 |
332 |
1 251 |
12.17 |
1.48 |
4.81 |
|
Total AO |
14 |
6 002 |
21 328 |
98.66 |
1.66 |
6.47 |
Tab 2.3.10.b: Area of Occupancy fragmentation indexes.
Probabilistic-continuous (PC) distribution model
The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.3.10.c.
Validation
No occurrence of the species within the four sample areas.
Comments and conservation issues
The suitable areas within the known EO of this species account for only 46 791 km2. Moreover, this area is highly fragmented and interspersed with areas that are of lower suitability or are definitely unsuitable. This pattern is confirmed by comparing the NP, MPS and LPI of the suitable areas, the moderately suitable areas and the total AO. The overall quality of the AO is greatly increased when the two types of areas are taken together. The CD model shows that some of the worst quality areas are in the northern parts of the range. Virtually none of the total AO is included in the protected areas of the region and the species is correctly classified as Vulnerable.
|
SUITABILITY CLASS |
inside |
outside |
Total |
|
suitable |
0.24 |
47.33 |
47.56 |
|
moderately suitable |
0.51 |
37.77 |
38.27 |
|
unsuitable |
0.19 |
13.97 |
14.16 |
|
Total |
0.94 |
99.06 |
100 |
Tab 2.3.10.c: Percent of environmental suitability classes within EO (as obtained from the categorical-discrete distribution model) inside and outside the protected areas.
References
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.
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.
Oates J.F. (1985). The Nigerian Guenon, Cercocebus erythrogaster: Ecological, behavioral, systematic and historical observations. Folia Primatol.: 45, 25-43.
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.
Stuart C., Stuart T. (1997). Field guide to the larger mammals of Africa. Struik Publishers.