Long-range juvenile dispersal and its implication for conservation of reintroduced swift fox Vulpes velox populations in the USA and Canada

Dispersal is fundamental to the persistence of wild populations. Historically, swift foxes Vulpes velox of the northern Great Plains of North America have been thought to be poor dispersers. Short-grass prairie is optimal habitat for swift foxes but can be fragmented in the northern Great Plains. We wanted to assess whether wild-born, juvenile swift foxes from two proximate but distinct reintroduced populations had potential to move from one population to the other. We found five animals exhibiting long bouts of dispersal, much further than averages previously reported. One female fox traversed the long distance between the two populations and survived for at least three breeding seasons in the wild. We believe our findings are significant for conservation because they show that swift foxes are not poor dispersers and that patches of short-grass prairie previously thought to be too isolated (> 25 km) for natural movement may be recolonized or be suitable for reintroductions of swift foxes.