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Primates
Id code: amd061Cercopithecidae
Allenopithecus nigroviridis
(Pocock, 1907)
(Eng) Allen's swamp monkey
(Fre) Cercopithèque noir et vert
Taxonomic notes
Formerly included in Cercopithecus. (Wilson & Reeder, 1993).
IUCN threat category
Lower Risk, near threatened (LR: nt).
Available information
Little is known on the species’ ecology. Most of the studies on the ecology of the species were carried out in former Zaire. Habitat use, population density, and coexistence with other primates were investigated in the Lomako Forest (former Zaire) by McGraw (1994). Some information on the species habitat is also available from Colyn (1987, 1988) and Lernould (1988). Notes on its feeding habits are found in Gautier-Hion (1988). Colyn and Lernould also report detailed data on its distribution. General information on the species’ ecology and distribution is given in Kingdon (1997) and Stuart & Stuart (1997). Status, distribution, and threats are discussed in Lee et al. (1988).
Known extent of occurrence
The distribution map was obtained from Lernould (1988) and the boundaries adjusted with the river network in accordance with Kingdon (1997). This species ranges in northwest former Zaire and northeast Congo, along the Zaire river and many of its tributaries (Lernould, 1988) (Fig. 2.3.1.a).
Categorical-discrete (CD) distribution model
This species is restricted to swamps, riverine forests and to adjacent drier, more open areas, including croplands (Kingdon, 1997; Lee et al., 1988).
Based on these environmental preferences, the following scores were assigned (Fig. 2.3.1.b) (Tab. 2.3.1.a):
|
Score |
|
|
1 |
Swamp forests; forests occurring inside a 1-km buffer around permanent water. |
|
2 |
Savannas and croplands occurring inside a 1-km buffer around permanent water. |
|
3 |
Forest mosaics, savannas and croplands occurring outside a 1-km buffer around permanent water. |
|
suitable |
moderately suitable |
unsuitable |
Total |
||||
|
km2 |
% |
km2 |
% |
km2 |
% |
km2 |
% |
|
362 189 |
63 |
6 866 |
1 |
210 121 |
36 |
579 176 |
100 |
Tab 2.3.1.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 |
375 |
970 |
16 672 |
87.36 |
1.45 |
14.15 |
|
moderately suitable |
218 |
30 |
13 |
0.03 |
1.04 |
1.09 |
|
Total AO |
352 |
1 052 |
17 553 |
89.12 |
1.49 |
14.27 |
Tab 2.3.1.b: Area of Occupancy fragmentation indexes.
Probabilistic-continuous (PC) distribution model
The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.3.1.c.
Validation
No occurrence of the species within the four sample areas.
Comments and conservation issues
The known EO of this species is significantly reduced when the species’ close association to water bodies is considered. About a third of the EO is thus classified as unsuitable as is shown by the CD model; the PC model, not considering the association with water bodies, smooths the suitability throughout the range. Overall fragmentation is limited (LPI = 89.12%) as a central block of suitable areas is available in central Zaire. About 6% of the total AO is protected, but the species is classified as Lower Risk.
|
SUITABILITY CLASS |
inside |
outside |
Total |
|
suitable |
2.10 |
60.44 |
62.54 |
|
moderately suitable |
0.11 |
1.08 |
1.19 |
|
unsuitable |
3.74 |
32.54 |
36.28 |
|
Total |
5.94 |
94.06 |
100 |
Tab 2.3.1.c: Percent of environmental suitability classes within EO (as obtained from the categorical-discrete distribution model) inside and outside the protected areas.
References
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.
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.
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.
McGraw S. (1994). Census, habitat preference and polyspecific association of six monkeys in the Lomako Forest, Zaire. Amer. J. Primatol.: 34 (4), 295-308.
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.