Are Norwegian lemmings Lemmus lemmus avoided by arctic Alopex lagopus or red foxes Vulpes vulpes?: A feeding experiment

Arctic fox Alopex lagopus and red fox Vulpes vulpes are close relatives with similar niche demands in the Holarctic. Where they are sympatric, they compete for territories, dens and food. Seat analyses from Fennoscandia have shown different proportions of lemmings and voles in the diets of the two fox species suggesting food partitioning. However, it was not clear if this was due to different food preferences or distinct habitat use. Since the arctic fox is an endangered species in Fennoscandia, it is important to know whether the superior, north spreading red fox can oust it from the tundra habitat, or if food specialisation may prevent displacement. In a feeding experiment at the Lycksele Zoo in northern Sweden, we compared the food preferences of two arctic and two red foxes. Our results show that the four individuals responded similarly to a variety of food items, and particularly that the two species were not distinct in their food preferences concerning lemmings and voles. However, the foxes had considerable individual predilections. Therefore, in the wild, the unequal proportions of lemmings and voles found in seats may reflect different habitat use for hunting.