Diets of east african bovidae based on stable isotope analysis

We provide stable carbon isotope data from 37 species of African bovids to document dietary preferences for C-3 browse (or fruits) or C-4 grass. These data provide a quantitative measure of the fraction of C-4 grass in bovid diets, can be applied on regional to local scales, can be derived from tooth enamel and hair or other tissues, and permit the diets of bovids to be considered in the context of a grazer-browser continuum. We recognize hypergrazers (>95% C-4 grass), grazers (70-95% C-4 grass), mixed feeders (>30% C-4 grass and >30% C-3 browse), browsers (70-95% C-3 browse), and hyperbrowsers or frugivores (>95% C-3 browse or fruit). Our results suggest that, of the extant East African Bovidae, impala (Aepyceros melampus), Thomson's gazelle (Gazella thomsonii), and oribi (Ourebia ourebi) can be construed as mixed feeders. Dietary estimates based on stable isotope analysis are in broad agreement with other measures of diet such as hypsodonty index, mass relationships, and wear scratches on enamel.