What does the fox say? Arctic fox vocalization and associated den behaviours

Foxes (Vulpes spp.) are small, solitary canids with relatively low social complexity compared to more gregarious canids, such as wolves and dogs. They are, therefore, expected to have a relatively simple vocal repertoire, with limited low-intensity sounds for close communication and many high-intensity sounds for long-distance communication. Arctic foxes (Vulpes lagopus), like many other foxes, are largely solitary outside of the breeding season. However, they have the largest litter size in the order Carnivora and may experience enhanced social complexity during the breeding season. In this study, we document the vocal repertoire of the Arctic fox during the breeding season, and how it changes before and after the emergence of pups. We also describe the relationship between vocalizations and other denning behaviours. Camera-traps captured six distinct sounds produced by breeding pairs of Arctic foxes and their young at dens: territorial barks, warning barks, alarm calls, cooing, whines and growling. Our study shows that although high-intensity sounds, such as territorial barks, are an important form of long-distance communication among Arctic foxes, low-intensity sounds and sound mixing are used on their dens following pup emergence. Thus, Arctic fox vocalization may be more complex than previously documented.