Evidence for Red Fox (Vulpes vulpes) Exploitation of Anthropogenic Food Sources along an Urbanization Gradient from Stable Isotope Analysis
Urban environments present a new set of challenges for wildlife such as navigating a busy landscape with dense roadways and increased human interactions. Species with ecological and behavioral flexibility can benefit from living in urban landscapes through lower investment in territory maintenance, sedentariness, and anthropogenic food scavenge. The red fox (Vulpes vulpes) is one species increasingly recognized as an urban community member. Red foxes have a generalist approach to diet which enables the species to use multiple food sources. We examined red fox exploitation of anthropogenic food sources as a function of degree of urbanization. We collected hair and stomach content samples from red foxes in Lancaster County, Pennsylvania for stable isotope analysis. We found the degree of anthropogenic food exploitation (1) increases with increasing areas of developed open spaces and impervious surface coverage and (2) decreasing areas of agricultural land use. A principal components analysis of seven metrics for urbanization revealed that the density of development was not driving exploitation. Instead, increasing habitat suitability, including vegetation coverage and large open spaces such as parks, lawns, and· golf courses, yielded higher levels of anthropogenic food exploitation. Large variation in the stable carbon isotope values among locations with similar landscape characteristics limited the predictive power of development metrics. This variation may be the result of fox migration form their home range to the sampling location or the spatial analysis did not take into account habitat use or actual home range size.
Franklin and Marshall College Archives, Undergraduate Honors Thesis 2013
- F&M Theses Collection