|The swift fox formerly
ranged from south-central Canada to northwestern Texas. There are
a number of subspecies, some of which may eventually be officially classified
as distinct species.
The northern variety has a number of
physical distinctions from that which inhabits the arid zones of the southwest.
Most notably, its coat is darker, it has a slightly broader skull, and
its ears are proportionately smaller. One subspecies, the San
Joaquin kit fox of California (V. velox mutica), has become
one of the most endangered, presumably due mainly to the use of poisoned
baits for the control of coyotes.