Vulpes velox the Swift Fox

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.

Vulpes zerda the Fennec Fox

Vulpes zerda the Fennec Fox

Figure 1: Fennec fox (Vulpes (Fennecus) zerda)

 

Weighing roughly one kilogram, the Fennec fox (Vulpes (Fennecus) zerda) is classified as the smallest canid (Macdonald, 2009). V. zerda is part of an old radiation, evolving 4 – 4.5 million years ago and was formerly separated as Fennecus due to its large ears, rounded skull, and “weak dentition” (Macdonald, 2009). This foxes distribution consists of the deserts of North Africa, continues throughout the Sahara and east to Sinai (Figure 2) (Macdonald, 2009; Kingdon, 1997).

V. zerda has numerous adaptations to life in the desert. The soles of the feet are covered in long, soft hairs that completely cover the pads (Macdonald, 2009; Larivière, 2002); this is an adaptation to extreme temperatures and facilitates easy movement in loose sand (Sheldon, 1992; Bekoff, 1975; Larivière, 2002; Nowak, 2005). The sandy colour of the coat camouflages the fox in the surrounding desert environments, an anti-predator adaptation, giving the fox an advantage in already harsh conditions. The thick coat also provides a thermoregulatory advantage during cold desert nights (Larivière, 2002). The Fennec fox will become cold with temperatures less than 20°C, and will neatly wrap its tail around its nose and feet to keep warm (Macdonald, 2009).

The enlargement of the bullae in the ears gives the Fennec fox excellent hearing (Larivière, 2002; Nowak, 2005).  This enables the fox to detect burrowing insects and small mammals (Larivière, 2002). Favouring desert grasshoppers and other invertebrates, such as, lizards, rodents and birds (Kingdon, 1997), V. zerda is similar to most other foxes as it is opportunistic omnivorous feeder, also consuming fruits and roots (Kingdon, 1997; Nowak, 2005).  The ability to hear prey underground is a fascinating adaptation that fox has evolved over time to gain an advantage in such harsh environmental and climatic conditions.

Vulpes chama the Cape Fox

Vulpes chama the Cape Fox

Figure 1: Cape fox (Vulpes chama)

The Cape fox (Vulpes chama) inhabits the steppe, rocky desert and open country of Southern Africa and South Zimbabwe and Angola (Figure 2) (Macdonald, 2009; Kingdon, 1997). V. chama is one of the least studied Vulpes species, and little is known about their diet (Klare et al., 2014). However, they are known to be opportunistic, feeding on invertebrates and mice, as well as other small vertebrates, fallen fruits and grass as well as any remains they find (Kingdon, 1997), simply any food they can find.

Predation upon this species has not been documented. Yet, it is likely that large birds of prey and larger carnivores in the area may predate on these foxes, especially the young. Cape foxes are rarely active in daylight and hunting is strictly confined to dark hours (Nel, 1984). This is a suggested behavioural adaptation to protect itself from any possible predators in the area.

Little is known about the evolution and adaptations of the Cape fox. However, the simple adaptations discussed above, opportunistic feeding and strict nocturnal hunting, could give this fox an advantage in surviving in such arid environmental conditions.