The corsac fox, also known simply as the corsac, is widespread in Central Asian countries from the Caspian Sea in the west to China in the east. It is a medium-sized fox common in steppes, semi-deserts and deserts. A special subspecies of this fox lives on the territory of Turkmenistan, which has the scientific name Vulpes corsac turkmenicus.
These foxes live in open grassy steppes and semi-deserts, avoiding dense vegetation and highlands. They also avoid true sandy deserts with drifting dunes, and in winter, areas with snow fields more than 15 cm (6 in) deep where cannot hunt. Corsacid foxes usually stay away from human settlements, unlike, for example, jackals.
The corsac fox is a medium-sized fox, with a head and body length ranging from 45 to 65 cm (18 to 26 in) and a tail from 19 to 35 cm (7.5 to 13.8 in). Adults weigh 1.6 to 3.2 kg (3.5 to 7.1 lb). It has gray or yellowish fur over most of its body, with a paler lower body and pale markings on its mouth, chin, and throat. In winter, the coat becomes much thicker and silkier.
The corsac is an opportunistic gatherer and hunter. Its diet varies throughout its range, but consists mainly of small to medium-sized vertebrates, insects, and small rodents such as voles, gerbils, jerboas, hamsters, and ground squirrels. It also readily feeds on larger prey, including hares and pikas. In order to adapt to the arid climate they live in, corsacs may forgo food and water for long periods of time.
Korsak is a nocturnal and nomadic steppe hunter. It does not have a protected territory and, unlike some foxes, sometimes forms packs. Natural predators of the corsac fox include gray wolf, leopard, Eurasian eagle-owl, eagles, and rarely the upland buzzard.
The mating season starts in January and ends in March. Males will initially fight for access to females, but will eventually form monogamous bonds and assist in raising the young. The mother first creates a maternity den, which is sometimes shared with other pregnant females, but moves her young to new dens several times after they are born.
Typically, two to six cubs are born after a gestation period of 52 to 60 days. Newborn puppies weigh about 60 g (2.1 oz) and have fluffy light brown fur that turns yellowish with age. They are born blind and open their eyes at about two weeks of age; they begin eating meat at four weeks and emerge from the den soon after. Foxes reach sexual maturity within 9–10 months and breed in their second year.