Full screen
Primates
Id code: amd327Galagonidae
Galagoides thomasi
(Elliot, 1907)
(Eng) Thomas's dwarf galago
(Fre) Galago de Thomas
Taxonomic notes
Still included in G. demidoff by some authors (e.g. Wilson & Reeder, 1993) it was recognised as a fully distinct species by Groves (1974) and this classification has also been adopted by Oates (1996).
IUCN threat category
Lower Risk, least concearn (LR: lc).
Available information
Literature available on this species is limited. The species' ecology was investigated in Makoku (Gabon) by Charles-Dominique (1971; 1977). Information on its habitat and other aspects of the species' ecology, particularly its behaviour, are found in Bourlière (1985) and Eisenberg et al. (1979). Data on its occurrence in the Gold Coast are reported in Booth (1979). General information on its ecology and distribution are reported in Kingdon (1997), Nash et al. (1989) and Stuart & Stuart (1997). Status and threats are discussed in Oates (1996).
Known extent of occurrence
The exact distribution of this species, generally lumped together with G. demidoff, is unclear. Its occurrence Nigeria, Cameroon, former Zaire, Uganda and Angola, in full sympatry with G. demidoff, is reported in Oates (1996) while the species' presence in western Africa, as well as in some central African countries, needs further investigation. Fig. 2.2.9.a was obtained from Kingdon (1997); uncertain records from Mt. Marsabit in Kenya are marked as "possible".
Categorical-discrete (CD) distribution model
This species occurs in low, medium altitude and montane forests; it also inhabits marginal forests (Nash et al., 1989; Rahm & Christiaensen, 1966).
Based on these environmental preferences, the following scores were assigned (Fig. 2.2.9.b) (2.2.9.a):
|
Score |
|
|
1 |
Forests. |
|
2 |
Forest mosaics. |
|
3 |
Savannas and croplands. |
|
suitable |
moderately suitable |
unsuitable |
Total |
|||||
|
OCCURRENCE |
km2 |
% |
km2 |
% |
km2 |
% |
km2 |
% |
|
certain |
2 041 059 |
48 |
923 977 |
22 |
1 233 756 |
29 |
4 198 792 |
99 |
|
possible |
23 |
0 |
34 |
0 |
27 190 |
1 |
27 247 |
1 |
|
Total |
2 041 082 |
48 |
924 011 |
22 |
1 260 946 |
30 |
4 226 039 |
100 |
Tab 2.2.9.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 |
1 439 |
1 419 |
45 267 |
57.51 |
1.25 |
29.19 |
|
moderately suitable |
3 266 |
283 |
4 789 |
7.78 |
1.29 |
11.83 |
|
Total AO |
1 033 |
2 872 |
77 042 |
82.42 |
1.28 |
24.7 |
Tab 2.2.9.b: Area of Occupancy fragmentation indexes.
Probabilistic-continuous (PC) distribution model
The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.2.9.c.
Validation
|
% of EO in sample areas |
Number of valid plots |
Index of Accordance (%) |
|
8.96 |
127 |
61.42 |
Tab 2.2.9.c: Categorical-discrete (CD) distribution model validation parameters.
Comments and conservation issues
The EO of this species is classified as 48% suitable and 22% moderately suitable, and these results are well supported by the Index of Accordance (61.42%). The two suitability classes combined provide a relatively continuous AO (LPI= 82.42), while the AWMSI indicates a rather articulate shape. Extensive unsuitable areas are shown at the southern and eastern boundaries, while potential available areas outside the known limit are indicated northward, and this pattern is confirmed by the PC model. Less than 4% of the AO is included in existing protected areas. These results, however, are only indicative as the species' distribution and ecology are poorly known and further research is urgent even though it is classified as Lower Risk.
|
OCCURRENCE |
SUITABILITY CLASS |
inside |
outside |
Total |
|
certain |
suitable |
1.79 |
46.50 |
48.30 |
|
moderately suitable |
0.68 |
21.18 |
21.86 |
|
|
unsuitable |
1.75 |
27.45 |
29.19 |
|
|
possible |
suitable |
0 |
0 |
0 |
|
moderately suitable |
0 |
0 |
0 |
|
|
unsuitable |
0.09 |
0.56 |
0.64 |
|
|
Total |
4.31 |
95.69 |
100 |
Tab 2.2.9.d: Percent of environmental suitability classes within EO (as obtained from the categorical-discrete distribution model) inside and outside the protected areas.
References
Booth A.H. (1979). The distribution of primates in the Gold Coast. In: Sussman R.W. (Ed.). Primate Ecology. Problem-oriented field studies. Wiley, Chichester & New York: chap. 7: 139-154.
Bourlière F. (1985). Primate communities: their structure and role in tropical ecosystems. Int J. Primatol.: 6, 1-26.
Charles-Dominique P. (1971). Eco-éthologie des prosimiens du Gabon. Biol. Gabonica: 7, 121-228.
Charles-Dominique P. (1977). Ecology and Behavior of Nocturnal Primates. Prosimians of Equatorial West Africa. Columbia University Press, New York.
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.
Groves C.P. (1974). Taxonomy and phylogeny of prosimians. In: Martin R.D., Doyle G.A., Walker A.C. (Eds). Prosimian Biology. University of Pittsburgh Press, Pittsburgh.
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.
Rahm U., Christiaensen A. (1966). Les mammiferès de l'Ile Idjwi (Lac Kivu, Congo). Les mammifères de la foret equatoriale de l'est du Congo. Ann. Mus. Roy. Afr. Cent.: n° 149.
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.