Page "Swift fox" Paragraph 4

The swift fox is closely related genetically to the kit fox ( Vulpes macrotis ), but occupies a different geographical range.

The two have historically been regarded as the same species for reasons basically related to size: the kit fox is slightly smaller than the swift fox, and the former has a narrower snout.

However, hybrids between the two occur naturally where their ranges overlap, and some mammalogists classify the two as subspecies of a single species, usually treated as Vulpes velox ( with the swift fox being described as V. velox velox and the kit fox as V. velox macrotis ).

The molecular genetics evidence is not conclusive however, and some of those who have used it continue to treat the swift fox and kit fox as separate species.