The Corsac fox is a species of Asian foxes. These medium-sized animals have grey to yellowish fur over much of the body, with paler underparts and pale markings on the mouth, chin, and throat. During the winter, their coat becomes much thicker and silkier in texture, and is straw-grey in color, with a darker line running down the back. Corsac foxes have keen eyesight and hearing and an acute sense of smell. They have a number of scent glands, some of which produce pungent odors. The glands are found in the anal region, above the base of the tail, and on the paws and cheeks.
Corsac foxes live in the central and northeast Asia. They are found throughout Kazakhstan, Uzbekistan, and Turkmenistan, and through all except the northernmost regions of Mongolia. In the south, their range extends into the more northern parts of Iran, Tajikistan, Kyrgyzstan, Afghanistan, and China, and they can also be found in neighboring regions of Russia. These foxes inhabit open grassy steppes and semideserts and avoid dense vegetation and mountainous regions. True deserts with drifting sands are also avoided, as are snowfields more than about 15 cm (6 in) deep. Corsac foxes generally stay far away from human disturbances.
Corsac foxes are nocturnal and nomadic hunters of the steppes. They do not have a defended territory, and sometimes form packs. Because they cannot hunt in deep snow, they will either shelter in their dens during harsh weather or, in the northern parts of their range, they may migrate up to 600 km (370 mi) south in the winter. They sometimes follow herds of local antelope, relying on them to compress the snow as they pass. Their prey is often buried in caches. Corsac foxes shelter in burrows from harsh weather and larger predators. Although they can dig their own dens, these are generally shallow, and they often take over the burrows of other animals. Dens may have several entrances but are usually less than 1 meter (3 ft 3 in) deep. The burrow is shared between the social packs, with several dens and connecting holes. Corsac foxes are excellent climbers, but are slow runners and could be caught easily by a dog. During hunting or when threatening rivals these foxes produce barks, and to use higher pitch yelps or chirps as alarm calls or social greetings.
Corsac foxes are omnivorous, mainly carnivorous animals. Their diet consists mainly of insects and small rodents, such as voles, gerbils, jerboas, hamsters, and ground squirrels. They may also eat larger prey, including hares and pikas, and will scavenge for carrion and human refuse. They do occasionally eat fruit and other vegetation, especially when animal prey is scarce. As an adaption to the arid climate in which they live, Corsac foxes need little water to survive, obtaining most of the moisture they need from their food.
Corsac foxes are monogamous and form pair bonds, however, before that males will initially fight for access to females. The breeding season starts in January and ends in March. The female creates a birthing den, which is sometimes shared with other pregnant females, but moves her young to new burrows several times after they are born. Typically, 2-6 kits are born after a gestation period of 52 to 60 days. However, the maximum recorded litter consisted of 11 kits. Newborn kits weigh around 60 g (2.1 oz) and have fluffy, light brown fur that turns yellowish as they age. They are born blind and open their eyes at around 2 weeks of age. Both parents assist in the raising of their young. Kits begin to eat meat at 4 weeks and emerge from the den shortly after. Corsac foxes reach reproductive maturity within 9 to 10 months and reproduce in the second year of life.
The major threat posed to the corsac fox is poaching. They are slow runners and are easily caught by hunters, and their population has been reduced in areas where they have been heavily hunted for their fur. In the late 19th century, up to 10,000 Corsac foxes were killed annually for pelt trade. The other main threats include overgrazing by livestock, landscape development, and natural disasters, which can cause the numbers of foxes to drop 90% in some areas.
The IUCN Red List and other sources do not provide the Corsac fox total population size, but this animal is common and widespread throughout its known range. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.