Edge effects on the density of Cheirogaleus major
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 ClassiÃ”Â¨Ã…ed 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 Octoberâ€šÃ„Ã¬November. 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 reÃ”Â¨Ã‡ect spatial variations in fruit and liana abundance, though data are needed on the precise relationship between tree diameter and food pro- duction to conÃ”Â¨Ã…rm 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.