Food subsidies of Raccoons in anthropogenic landscapes

Food subsidies from human sources are often exploited by free-ranging vertebrates living in human-dominated landscapes. To explore the importance and attempt to estimate the reliance of raccoons (Procyon lotor Linnaeus, 1758) – common synanthropes in North America – on such food subsidies, we analyzed hair samples from 122 raccoons collected across four states in Midwestern North America (Wisconsin, Minnesota, Iowa and Illinois), including 9 raccoons that were live-trapped and sampled in Madison, Wisconsin USA. We found that raccoons inhabiting areas with more agriculture had higher δ13C values, indicating a diet enriched with anthropogenic food from C4 photosynthetic plants, like Zea mays L. Surprisingly, raccoons inhabiting increasingly urban areas showed lower δ13C values, suggesting a diet with less anthropogenic food. Regardless, raccoons in urban areas enriched in 13C possessed high indices of body condition, suggesting that anthropogenic food subsidies are contributing to their overall nutritional condition. Our findings reveal that the degree to which synanthropes rely upon human foods differs by land cover type, and that the use of these calorically-rich subsidies has important implications on individual health.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author