What does the fox select? Spatial ecology of Rocky Mountain red fox during peaks and troughs of human recreation

Abstract

Understanding animal behavior at the population level can be challenging, especially in the presence of intraspecific variation in behavioral tactics. Individuals within a population often vary with respect to resource exploitation and use, which may be associated with individual states (e.g., male or female) or extrinsic variation (e.g., temporal variation in food). Explicitly accounting for interindividual variation can aid ecological insights, especially for species that exhibit high behavioral flexibility. Here, we evaluated how seasonal fluctuations in resources influenced individual-level habitat use and selection of Rocky Mountain red fox (Vulpes vulpes macroura) within Grand Teton National Park, Wyoming. Rocky Mountain red fox is a high-elevation subspecies of the common red fox (Vulpes vulpes), and native to North America. From 2016 to 2021, we captured and GPS-collared 18 individuals (11 males, 7 females) and evaluated spatiotemporal shifts in home range characteristics and habitat selection. We observed high individual variation in home range size, with generally larger home ranges in the winter months ($\overline{x}$ = 72.92 km² [minimum convex polygon—MCP], 83.65 km² [Kernel], 27.20 km² [Local Convex Hull]) than in the summer ($\overline{x}$ = 22.23 km² [MCP], 23.01 km² [Kernel], 11.11 km² [Local Convex Hull]). Similarly, we observed substantial individual variation in habitat selection across environmental gradients. Some foxes altered their selection for habitat types between summer and winter indicating behavioral plasticity with respect to seasonal resources. Distance to human features was the primary driver for habitat selection for both seasons across foxes, and on average, foxes had stronger selection for human features in the summer. These findings might indicate some foxes are concentrating on the temporal and spatial resource pulse of anthropogenic food, while others exhibited more natural tactics. Our work advanced the spatial ecology of Rocky Mountain red fox, identified variation in space use tactics associated with humans and natural resources among red foxes in a heavily recreated area, and demonstrated how human activity can influence the spatial behavior of a carnivore within a national park.