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Primates
Id code: amd298Galagonidae
Euoticus pallidus
(Gray, 1863)
(Eng) Pallid needle-clawed bushbaby
(Fre) Galago mignon du nord
Taxonomic notes
Formerly included in the genus Galago, it has been recognised as distinct by Groves (1989) and was recently accepted as such by the IUCN (Oates, 1996).
IUCN threat category
Lower Risk, near threatened (LR: nt).
Available information
Literature available on the species' ecology is scarce. Its presence on Bioko Island is described in Butynski & Koster (1994). General information on its ecology and distribution is found in Kingdon (1997), Nash et al. (1989) and Stuart & Stuart (1997). Status, threats, and notes on its ecology are reported in Oates (1996).
Known extent of occurrence
E. pallidus ranges on Bioko Island (in Eq. Guinea) and in Cameroon and Nigeria between the Cross and Sanaga Rivers (Wilson & Reeder, 1993; Kingdon, 1997). The source for its distribution was Nash et al. (1989), but the map was revised on the basis of information in Oates (1996) and Kingdon (1997) to match the river network cover (Fig. 2.2.2.a).
Categorical-discrete (CD) distribution model
This species prefers primary and secondary rain forests (Kingdon, 1997; Nash et al., 1989).
Based on these environmental preferences, the following scores were assigned (Fig. 2.2.2.b) (2.2.2.a):
|
Score |
|
|
1 |
Forests. |
|
2 |
Forest mosaics. |
|
3 |
Savannas and croplands. |
|
suitable |
moderately suitable |
unsuitable |
Total |
||||
|
km2 |
% |
km2 |
% |
km2 |
% |
km2 |
% |
|
61 560 |
54 |
40 300 |
35 |
12 903 |
11 |
114 763 |
100 |
Tab 2.2.2.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 |
55 |
1 112 |
5 362 |
38.39 |
1.49 |
7.4 |
|
moderately suitable |
108 |
371 |
1 572 |
12.75 |
1.41 |
4.96 |
|
Total AO |
7 |
14 457 |
34 662 |
98.17 |
2.07 |
6.92 |
Tab 2.2.2.b: Area of Occupancy fragmentation indexes.
Probabilistic-continuous (PC) distribution model
The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.2.2.c.
Validation
|
% of EO in sample areas |
Number of valid plots |
Index of Accordance (%) |
|
85.02 |
29 |
48.28 |
Tab 2.2.2.c: Categorical-discrete (CD) distribution model validation parameters.
Comments and conservation issues
Although it must be taken with the caution dictated by the low Index of Accordance (48.28%), the small EO of this species consisting mainly of a mosaic of suitable (54%) and moderately suitable (35%) areas, is classified as largely suitable by the CD model. The two classes combined provide an almost continuous AO (LPI = 97.85%), but unsuitable areas are frequent in Cameroon and scattered throughout the range. About 5% of the total AO is included in existing protected areas. The species' status and ecology are poorly known and further research is urgent even though the species is classified as Lower Risk.
|
SUITABILITY CLASS |
inside |
outside |
Total |
|
suitable |
2.68 |
50.96 |
53.64 |
|
moderately suitable |
1.59 |
33.52 |
35.12 |
|
unsuitable |
1.21 |
10.03 |
11.24 |
|
Total |
5.49 |
94.51 |
100 |
Tab 2.2.2.d: Percent of environmental suitability classes within EO (as obtained from the categorical-discrete distribution model) inside and outside the protected areas.
References
Butynski T.M., Koster S.H. (1994). Distribution and conservation status of primates in Bioko Island, Equatorial Guinea. Biodiversity Conserv: 3(9), 893-909.
Groves C.P. (1989). A theory of human and primate evolution. Oxford University Press, New York.
Kingdon J. (1997). The Kingdon field guide to African Mammals. Academic Press, London and New York: Natural World.
Nash L.T., Bearder S.K., Olson T.R. (1989). Synopsis of Galago species characteristics. Int J. Primatol.: 10, 57-80.
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.
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.