Vulpes velox the
Swift Fox
Figure 1:
Swift fox (Vulpes velox)
The
swift fox (Vulpes velox) ranges from
Central USA from Texas to South Dakota and has been reintroduced into Canada
and Montana (Figure 2), they also
form a hybrid zone with Kit foxes (Vulpes
macrotis) in New Mexico (Macdonald, 2009). This fox inhabits prairies,
especially those with short or medium height grasses (Nowak, 2005; Macdonald,
2009). Burrows can either be self-excavated or taken over from another mammal
(Nowak, 1999).
The
swift fox was rarely seen in the northern Great Plains between 1900 and 1970 and
appeared to be completely exterminated in Canada by hunting and poisoning (Macdonald,
2009). However, as mentioned earlier this fox has now been successfully reintroduced
to the Canadian prairies, where the main threat to this species is predation by
coyotes, golden eagles, and there is a potential threat through competition from
the spread of red foxes (Macdonald, 2009).
This fox is an adaptable nocturnal
hunter, feeding on lagomorphs, rodents and other small prey animals, such as,
lizards, birds and insects (Kays & Wilson, 2009). By having such a large
range of foods in their diet they are able to predate on foods that are
seasonally available, giving them an advantage in their surrounding
environmental conditions. During the day
the fox will predominately stay in the den although, they are known to sun
themselves near the entrance (Kays & Wilson, 2009). While not proven, this
could be both a behavioural anti-predator adaptation and a thermoregulatory that
this fox has gained over time to give itself the best possible chance of
survival in the surrounding environment.
I’ve been meaning to ask this for a while. Is there the potential threat to all these foxes, particularly the swift fox, from inter-breeding and hybridization with red foxes, which are quite successful invaders in many areas? Do you know if someone has developed a phylogenetic tree looking at the relationships of the different foxes?
ReplyDeleteThank you for an interesting and enlightening look at the evolution of species in this genus. I have enjoyed reading your blogs and have learned a great deal about a group of animals that I didn’t realise were so diverse.
Apart from the cape fox, whose range does not over lap with the red fox's distribution at all, and the Fennec fox whose range only boarders that of the red fox, the red fox does pose a threat to all other foxes discussed. Although most of the foxes are opportunistic, the red fox is more of a generalist species and, thus has the largest distribution of all the foxes. I have not found any information thus far that suggests inter-breeding and hybridisation, that said it does not mean it is not possible. However, offspring would be inviable/infertile. Rather, the red fox is able to utilise more resources, consequently, not leaving enough resources for the remaining species in the area.
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