PRIMATES

Full screen Primates Id code: amd059

Galagonidae
Galago senegalensis

É. Geoffroy, 1796

(Eng) Lesser bushbaby

(Fre) Galago du Sénégal

Taxonomic notes

In accordance with Oates (1996) and Wilson & Reeder (1993), the lesser bushbaby is considered here to be separate from both G. gallarum and G. moholi.

IUCN threat category

Not listed.

Available information

Literature available on the ecology of this species is limited. A captive study on behavioural aspects of its ecology was carried out by Zimmerman (1989). Some information on the species’ presence and density is reported in Varty (1988), where the author analysed the mammal fauna of the riverine forest of the Jubba Valley (Somalia). Data on the species’ occurrence and notes on its ecology are available for eastern former Zaire (Rahm & Christiaensen, 1966), Ghana (Booth, 1979), Ethiopia and Eritrea (Yalden et al., 1977, 1996), and Somalia (Funaioli, 1971). General information on its ecology and distribution is found in several authors (Charles-Dominique, 1977; Estes, 1991; Kingdon, 1971-77, 1997; Nash et al., 1989; Stuart & Stuart, 1997). Status and threats are discussed in Oates (1996).

Known extent of occurrence

G. senegalensis occurs from Senegal to Ethiopia and probably as far south as to north Mozambique. A distribution map was obtained from Nash et al. (1989) and then updated on the basis of Kingdon (1997). The boundaries of the species’ range in east Africa, however, remain uncertain and in parts of it the distribution has been marked as "possible" (Kingdon, 1997) (Fig. 2.2.7.a).

Categorical-discrete (CD) distribution model

The species inhabits a broad range of habitat types outside the main forest block; it is found mainly in bushlands and woodlands (Yalden et al., 1977; Kingdon, 1997; Nash et al., 1989; Booth, 1979).

Based on these environmental preferences, the following scores were assigned (Fig. 2.2.7.b) (Tab. 2.2.7.a):

Score
1	Woodlands, bushlands and thickets.
2	Other savanna types and degraded forest outside the main forest block.
3	Forests and croplands

	suitable		moderately suitable		unsuitable		Total
OCCURRENCE	km²	%	km²	%	km²	%	km²	%
certain	3 769 621	44	2 596 650	30	1 302 806	15	7 669 077	89
possible	611 219	7	213 261	2	123 667	1	948 147	11
Total	4 380 840	51	2 809 911	33	1 426 473	17	8 617 224	100

Tab 2.2.7.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	3 427	1 278	57 199	45.61	1.26	41.37
moderately suitable	5 479	513	10 429	8.85	1.33	17.83
Total AO	1 095	6 570	213 065	98.05	1.26	35.9

Tab 2.2.7.b: Area of Occupancy fragmentation indexes.

Probabilistic-continuous (PC) distribution model

The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.2.7.c.

Validation

% of EO in sample areas	Number of valid plots	Index of Accordance (%)
5.81	175	63.43

Tab 2.2.7.c: Categorical-discrete (CD) distribution model validation parameters.

Comments and conservation issues

The most widespread of all Galago spp., it is less closely associated to forests than the other species. Suitable areas account for 44% of the EO and moderately suitable areas for another 30%. Unsuitable areas are more frequent in the areas along the northern limits of the EO in western Africa, Sudan, Ethiopia, Kenya and Uganda. The zone of "possible " presence in Tanzania appears to be quite suitable although the PC model identifies large less suitable areas there. Accordance of the CD model with field work results is of 63.43%, which should be regarded as quite high, as the species is widely distributed and has rather broad habitat preferences. Fragmentation is very severe as shown by the NP and MPS. The LPI of the suitable areas is greatly improved by the contribution of the moderately suitable areas and that of the total AO indicates the availability of one large continuous patch. However, the AWMSI are high for all areas, indicating that all areas of different suitability are highly intersected in an intricate spatial mosaic. The species is not threatened. About 7.8% of the total AO is included in existing protected areas.

OCCURRENCE	SUITABILITY CLASS	inside	outside	Total
certain	suitable	3.65	40.10	43.75
	moderately suitable	2.12	28.01	30.13
	unsuitable	1.20	13.92	15.12
possible	suitable	1.13	5.96	7.09
	moderately suitable	0.22	2.25	2.47
	unsuitable	0.16	1.28	1.44
Total		8.48	91.52	100

Tab 2.2.7.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.

Charles-Dominique P. (1977). Ecology and Behavior of Nocturnal Primates. Prosimians of Equatorial West Africa. Columbia University Press, New York.

Estes R.D. (1991). The Behavior Guide to African Mammals. Including Hoofed Mammals, Carnivores, Primates. The University of California Press.

Funaioli U. (1971). Guida breve dei mammiferi della Somalia. Istituto Agronomico per l'Oltremare. Biblioteca Agraria Tropicale.

Kingdon J. (1971-77). East African Mammals. VOL I: primates, hyraces, pangolins, protoungulates, sirenians. VOL IIA: Insectivores and bats. VOL IIB: hares and rodents. VOL IIIA: carnivores. VOL IIIB: large mammals. VOL IIIC: bovids. VOL IIID: bovids. Academic Press, London and 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.

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.

Varty N. (1988). Mammals and problems of their conservation in the riverine forests of the Jubba Valley, southern Somalia. Tropical Zoology: 1, 179-192.

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.

Yalden D.W., Largen M.J., Kock D. (1977). Catalogue of the mammals of Ethiopia 3. Primates. Monitore Zoologico Italiano: suppl. IX, 1-52.

Yalden D.W., Largen M.J., Kock D., Hillman J.C. (1996). Catalogue of the mammals of Ethiopia and Eritrea. 7. Revised checklist, zoogeography and conservation. Tropical Zoology: 9, 73-164.

Zimmerman P. (1989). Aspects of reproduction and behavioral and vocal development in Senegal bushbabies (Galago senegalensis). Int J. Primatol.: 10(1), 1-16.