St. Matthew Island colonized through multiple long-distance red fox (Vulpes vulpes) dispersal events

Expansion of red fox (Vulpes vulpes (L., 1758)) into new arctic habitat and the potential for competition with arctic fox (Vulpes lagopus (L., 1758)) are of considerable conservation concern. Previous work has focused on red fox expanding into contiguous areas with few barriers to dispersal. Here, we examine mitochondrial DNA in red fox on recently colonized St. Matthew Island in the Bering Sea to determine their ultimate origin. Though limited in sample size (n = 7), we found that St. Matthew Island was colonized by North American lineages; surprisingly, despite the >400 km distance to the mainland, we found the island was colonized by at least three mitochondrial matrilines. These results suggest that even extremely isolated places may be colonized by red fox, and that the over-ice or over-ocean dispersal ability of red fox may have been previously underappreciated.