title: Intergroup variation in stable isotope ratios reflects anthropogenic impact on the Barbary macaques (Macaca sylvanus) of Gibraltar.
abstract: Interactions with humans impact many aspects of behavior and ecology in nonhuman primates. Because of the complexities of the human-nonhuman primate interface, methods are needed to quantify the effects of anthropogenic interactions, including their intensity and differential impacts between nonhuman primate groups. Stable isotopes can be used to quickly and economically assess intergroup dietary variation, and provide a framework for the development of specific hypotheses about anthropogenic impact. This study uses stable carbon and nitrogen isotope analysis to examine intraspecific variation in diet between five groups of Barbary macaques, Macaca sylvanus, in the Upper Rock Nature Reserve, Gibraltar. Analysis of hair from 135 macaques showed significant differences in δ(13)C and δ(15)N values between a group with minimal tourist contact and groups that were main tourist attractions. Because we observed no overt physiological or substantial behavioral differences between the groups, feeding ecology is the most likely cause of any differences in stable isotope ratios. Haphazard provisioning by tourists and Gibraltarians is a likely source of dietary variation between groups. Stable isotope analysis and observational data facilitate a deeper understanding of the feeding ecology of the Barbary macaques relevant to the role of an anthropogenic ecology for the species.
authors: Department of Anthropology, University of Notre Dame, Notre Dame, IN 46556, USA.
authors: Mark R
authors: MR
authors: Schurr
authors: Agustín
authors: A
authors: Fuentes
authors: Ellen
authors: E
authors: Luecke
authors: John
authors: J
authors: Cortes
authors: Eric
authors: E
authors: Shaw
mesh_terms: D017677:Age Distribution; D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis*; D004032:Diet / Q000145:classification / Q000662:veterinary*; D005260:Female; D005876:Gibraltar; D006197:Hair / Q000737:chemistry*; D006802:Human Activities; D006801:Humans; D008251:Macaca / Q000378:metabolism*; D008297:Male; D013058:Mass Spectrometry / Q000662:veterinary; D009587:Nitrogen Isotopes / Q000032:analysis*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes