Red foxes in Japan show adaptability in prey resource according to geography and season: A meta‐analysis

Abstract

AbstractThe red fox (Vulpes vulpes) is the world's most widespread member of the order Carnivora, occurring across a large range of latitudes and inhabiting multiple habitat types. There is no comprehensive study of how the diets of this flexible generalist vary across the whole Asian continent. We conducted a meta‐analysis of red fox diets in Japan, examining the patterns in food type selection and their associations with seasonality, regional climate, vegetation productivity, and human influences at the national scale. Using linear mixed models, we revealed significant seasonal effects on the frequency of occurrence of mammals in general, ungulate carcasses, birds, and invertebrates in the diets of red foxes. Furthermore, the frequency of occurrence of mammals significantly decreased with mean annual temperature and increased with vegetation productivity. The frequency of invertebrate occurrences increased with temperature, and that of anthropogenic foods increased with human population density. Trophic diversity and dietary niche breadth increased with annual temperature but decreased with vegetation productivity and population density. These results suggest that the red fox is a flexible predator in Japan that adapts its foraging patterns according to variations in resource availability and abiotic conditions, while persistently consuming a certain ratio of animal prey to meet its metabolic requirements. Modifications of predators' trophic niches can influence structures of prey communities and interactions with sympatric competitors. Our findings are important for informing ecosystem management practices under ongoing environmental and social changes in Japan.