Vulpes corsac the Corsac Fox

Vulpes corsac the Corsac Fox

                     Figure 1: Vulpes corsac (Corsac Fox).

The Corsac fox (Vulpes corsac) is a typical fox-like canid that inhabits dry steppes, semi deserts and deserts throughout Middle Asia (Kazakhstan, Turkmenistan, Uzbekistan), Northern Afghanistan to Mongolia, North and North East China (Figure 2) (Macdonald, 2009; Macdonald & Sillero-Zubiri, 2004). This fox, like many others, lives in a burrow that is often taken over from another mammal, such as a badger (Nowak, 1999). V. corsac is an excellent climber, with exceptional senses of vision, hearing and smell (Nowak, 1999). This foxes ability to climb allows it to widen its diet to animals that live in trees, such as birds and arboreal reptiles. The Corsac foxes diet is also made up of small rodents, insects and plant material, this omnivorous diet allows the fox greater chance at survival by increasing the number of different types of food it is able to consume (Clark et al., 2009). Yet, due to this foxes habitat range, it has adapted to arid conditions and can forego food and water for extended periods (Clark et al., 2009), these adaptations have given the Corsac fox advantages in surviving in such harsh conditions.

V. corsac is reported to be nomadic and does not keep to a fixed home range (Ognev, 1962). The Corsac fox may migrate southwards when deep snow and ice make hunting difficult (Stroganov, 1969), allowing a greater chance of survival as it increases the likeliness of prey availability. A second reason for migrating southwards may be, though the cortex and medulla features of its fur allow it to endure cold, harsh winter conditions it is not adapted for walking on snow (Clark et al., 2009). This migration to the South when conditions become to harsh is a simple behavioural adaption that shows how this species of fox has evolved over time to give itself the best possible chance of survival within its environment niche, habitat and climatic conditions.

Vulpes rueppellii the Rüppell’s Fox

Vulpes rueppellii the Rüppell’s Fox

Figure 1: Vulpes rueppellii (Rüppell’s fox).

The Rüppell’s fox (Vulpes rueppellii) is a small desert species that ranges through North Africa, eastwards from Morocco to Egypt, through the Arabian Peninsula to Afghanistan and Western Pakistan (Macdonald, 2009). As this foxes habitat is mainly sand and stone deserts its fur is a pale, sandy to reddish colour (Macdonald, 2009). As the fur of these animals is closely matched to the surrounding environment, it helps conceal them from predators. This simple yet effective adaptation has given this species an advantage in surviving in such harsh conditions.

Possibly the most interesting adaptation of the foxes is hidden within the violet (tail) glands. Females have a well-developed violet gland that is used to scent mark the den site (Mech and Boitani, 2003). This gland also has a special skunk-like ability. When threatened, a fox will hump back, raise its tail, and squirt a noxious anal secretion at potential predators (Kingdon, 1997). Although this is one fascinating adaptation, due to the predominately inhospitable habitat that this fox occupies, Rüppell’s foxes have fewer predators than other species within this genus. Main predation is aerial such as Steppe eagles and Eagle owls (Larivière and Seddon, 2001). However, this bizarre adaptation is still a good example of how this fox has been able to adapt itself over time to have the best chance of survival within its environment niche, habitat and climatic conditions.

Vulpes vulpes the Red Fox

Vulpes vulpes the Red Fox

Figure 1: Vulpes vulpes (Red Fox) ‘Fox posing for the camera’.

The Red Fox (Vulpes vulpes) evolved roughly 4 – 4.5 million years ago and is the largest fox within the Vulpes genus (Macdonald, 2009). It is natively found in the northern hemisphere from the Arctic Circle to North African and Central American deserts and has been introduced into Asiatic steppes (Figure 2) (Macdonald, 2009). This fox has been forced to adapt to multiple habitats due to its extensive range. During the autumn and winter, the fox will grow a thicker pelt; this "winter fur" keeps the animal warm in the colder environments. The newly grown fur will then shed at the onset of spring, reverting back to short fur for the duration of the summer (Macdonald, 1988), this is one example of how this species has adapted itself to best suit its surrounding environments and climatic conditions.

V. vulpes are skilful predators. Their prey includes insects, small mammals and sometimes birds (Henry, 1986). However the Red Fox is omnivorous, feeding on plants as well as animals, typically eating ½ to 1kg of food a day, roughly 10% of its body weight (Amaike et al., 2015). The Red Fox is an opportunistic feeder that samples any acceptable food, taking advantage of any seasonally abundant food (Henry, 1986). These abilities to grow a thick pelt in the winter and to change diet from season to season shows how this animal is a highly adaptable species that is able to occupy many different environments, niches and habitats and adapt itself to have the best possible chance at survival.

Vulpes: The Evolution of Foxes - An Introduction

Vulpes: The Evolution of Foxes - An Introduction

Figure one: Various true foxes: left to right, top to bottom: Vulpes vulpes, Vulpes rueppellii, Vulpes corsac, Vulpes bengalensis, Vulpes lagopus, Vulpes cana, Vulpes chama, Vulpes zerda and Vulpes velox.

Vulpes is the genus of foxes within the Canidae family. The members of this genus are colloquially referred to as true foxes, as the cluster includes many of the Old World species (Macdonald, 2009).  This genus is compromised of numerous species that inhabit a wide range of habitats and climatic conditions (Kumar, et al., 2015). The appearance of species within the genus include: a pointed muzzle, triangular and erect ears, a long and bushy tail, a flattened skull (when compared to Canis), the tip of the tail is generally a different colour to that of the rest of the coat with black triangular face marks between the eyes and nose (Macdonald, 2009). Each of the following species has evolved differently to best suit its environment niche, habitat and climatic conditions that have all shaped this Old World genus.  The Red fox (Vulpes vulpes), Rüppell’s fox (Vulpes rueppellii), Corsac fox (Vulpes corsac), Bengal fox (Vulpes bengalensis), Arctic fox (Vulpes lagopus), Blanford’s fox (Vulpes cana), Cape’s fox (Vulpes chama), Fennec fox (Vulpes zerda) and swift fox (Vulpes velox).  This blog aims to demonstrate how each species has evolved to best suit its surrounding environment.