Swift foxes are so unsuspicious that they are easily trapped, and even more easily poisoned. Consequently, wherever trappers are active, and especially wherever control campaigns involving the use of poison have been carried out against predatory animals on areas inhabited by swift foxes, the foxes have been greatly reduced in number or entirely eliminated. Habitat loss due to agricultural, industrial and urban development is also a threat. Dens have been ploughed over and native grasses replaced with tall cereal crops that are unsuitable for foxes or their food.
Vulpes velox is the smallest of the American foxes. These small foxes, not much larger than a large house cat, generally inhabit the open desert or grasslands where they have dens and hunt along the borders of valleys, sparsely vegetated habitats on sloping plains, hilltops, and other well-drained areas. Vulpes velox has adapted to pasture, ploughed fields, and fence rows.
The swift fox and the kit fox Vulpes macrotis were originally considered as two separate sub-species, now they are regarded as the same.
Other language names: French: Renard véloce.
Vulpes velox was extinct in all of Canada until about two decades ago when attempts were first made to reintroduce them. The Swift fox disappeared entirely from Canada in the early 1900s. Reintroduction programmes in the last 15 years have established a small population of 150-200 in the southern prairies of Alberta and Saskatchewan.
Vulpes velox is considered as a "Lower Risk" sub-category "conservation dependent" by the IUCN. CITES lists the species as "Appendix 1".