The 85th Annual Meeting of the American Association of Physical Anthropologists (2016)


Food patch characteristics and dynamics of patch use and sharing in two sympatric lemur species at Tsinjoarivo, Madagascar

MEREDITH A. KEELEY1, MITCHELL T. IRWIN2,3 and JEAN-LUC RAHARISON3.

1Biology, Queens University of Charlotte, 2Anthropology, Northern Illinois University, 3Division of Research, NGO Sadabe

April 16, 2016 , Atrium Ballroom A/B Add to calendar

Individuals’ access to food patches is impacted by within-group competition, but also depends fundamentally on the size and quality of patches available; feeding patch volume and richness likely influence the time feeding there and the likelihood of sharing/revisits. We quantified resource patch characteristics, use, and sharing in two lemur species at Tsinjoarivo, Madagascar. First, we used 9-10 day-long full-group focal samples (following all group members simultaneously), recording each feeding bout and marking each food patch with a flag and unique identifier; this identifier was recorded for each subsequent use by any animal. Second, we measured crown dimensions and estimated volume for each patch. Common Brown Lemurs (Eulemur fulvus) used larger patches (median: 25 m3, n=174), a greater percentage of which were used by multiple individuals (70%); Diademed Sifakas (Propithecus diadema) used smaller patches (median: 13 m3, n=678) and shared less often (43%). There was a significant linear relationship between crown volume and the number of animals seen using the patch but the amount of variation explained was low (P. diadema: R2 = 0.02; E. fulvus: R2=0.14). The dominant female was first to feed in a disproportionately high percentage of shared patches (E. fulvus 32%, expectation 14%; P. diadema 33%, expectation 20%; X2 test P<0.001), suggesting that dominance facilitates priority access for some patches. In sum, much feeding is solitary but female dominance is evident in patch entry order; more work is necessary to better define the conditions, season, and/or social contexts in which female dominance translates directly into fitness benefits.