Edge effects on the density of Cheirogaleus major
Lehman S; Rajaonson A; Day S
International Journal of Primatology
We investigated how greater dwarf lemur (Cheirogaleus major) densities ambient air temperature and dendrometrics (tree height and diameter) var- ied along forest edge-interior gradients in the Vohibola III ClassiÔ¨Åed For- est in SE Madagascar. We also assessed if spatial variations in densities of Cheirogaleus major provide indirect evidence of increased predation pres- sure in the transition zone between edge and interior forest habitats i.e. an ecological trap. We conducted diurnal temperature surveys (N = 394) and nocturnal surveys of Cheirogaleus major (N = 182) over 2 yr along 4 1250- m transects that ran perpendicular to the forest edge in Vohibola III. We did not see Cheirogaleus major from May to mid-September and the highest sighting frequency occurred during October‚ÄìNovember. Cheirogaleus major exhibited a negative edge response because densities ranged from low levels in edge habitats to higher levels in the forest interior. After we tested for spatial autocorrelation edge-related variations in densities of Cheirogaleus major covaried most strongly with tree diameter. Edge responses of Cheirogaleus major may reÔ¨Çect spatial variations in fruit and liana abundance though data are needed on the precise relationship between tree diameter and food pro- duction to conÔ¨Årm the relationship. Edge-related variations in densities of Cheirogaleus major may also provide indirect evidence of an ecological trap. Testing and controlling for spatial autocorrelation should be important com- ponents of future studies of primate conservation biology and ecology.