1Anthropology, University of North Dakota, 2Anthropology, University of Colorado-Boulder, 3Anthropology, University of Arkansas
Saturday All day, Plaza Level
Tooth wear rates are assumed to be consistent across individuals in single primate populations, with wear stages frequently used as a proxy for estimating ages of unknown individuals, including fossils. We present tooth wear rates in a single ring-tailed lemur population from the Beza Mahafaly reserve, southwestern Madagascar. Individuals (n = 32) are first captured at two years old, are recaptured annually and are of known age. Wear rates were calculated based on yearly ordinal wear scores across three field seasons, and were compared by sex and across and within two microhabitats. Females living in the non-river margin microhabitat show significantly lower rates of molar wear (p = 0.0069) than females in the river margin area of the reserve. Females in the non-river margin microhabitat have lower molar wear rate (p = 0.0008) than males in the same microhabitat, but no sex differences occurred within the river margin microhabitat. Male rates did not differ between the two microhabitats. Higher male wear rate in the non-river margin microhabitat likely reflects their more frequent use of mechanically challenging tamarind fruit. Higher rate of wear among river margin females probably results from using physically challenging foods, especially introduced plants not used by lemurs living away from the river margin. Our data illustrate that within species, individual tooth wear rates can vary substantially both between and within groups. This lack of a species-specific wear rate suggests that use of this attribute as a proxy for age of fossil primates should be approached with caution.
Funding – National Science Foundation BCS-0922465