Abstract # 3174 Poster # 171:

Scheduled for Sunday, September 18, 2011 07:00 PM-09:00 PM: Session 23 (Salon G (Sixth Floor)) Poster Presentation


MICROHABITAT INFLUENCES ON HABITAT USE BY BLACK-AND-WHITE RUFFED LEMURS (VARECIA VARIEGATA) IN A FRAGMENTED LANDSCAPE AT KIANJAVATO-VATOVAVY, MADAGASCAR

S. M. Holmes, T. M. Wyman and S. E. Johnson
University of Calgary, Department of Anthropology, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
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Primates typically use forest environments in a heterogeneous way, with sometimes strong preferences for particular microhabitats. Black-and-white ruffed lemurs (Varecia variegata) are a critically endangered species, with a large overall range but with a patchy distribution within that range. They have been noted to be highly sensitive to habitat type and change. We therefore predict that habitat use by V. variegata will be influenced by microhabitat characteristics within forest fragments at Kianjavato-Vatovavy. We followed two communities (N=16 individuals) in two fragments for two weeks each per month from June to September 2010 (N=415 hours). Using logistic regression, we tested if occupancy was influenced by tree metrics (dbh, crown diameter, basal area, food species basal area, species diversity, canopy cover, crown connectivity), as well as topographic/landscape characteristics (slope, elevation, distance to forest edge) among 0.04 ha plots (N=35) within and outside the seasonal range as defined by minimum convex polygon adjusted to grid cells. Although the models were significant, no individual variables significantly predicted occupancy (p=0.997-1.000 ns). Combining sites for analysis, tree species diversity was the only significant variable (chi-square (10,35)=20.8; p=0.023; odds ratio=37.8; p=0.024). Diversity has been found to influence lemur population dynamics elsewhere in Madagascar. There may also be other important, untested ecological factors (e.g., predation risk). Further analyses, including finer scale investigation of use intensity, may reveal additional characteristics influencing patchy range use.