and behavior As an adaption to the arid climate in which they live, corsac foxes can forego food and water for extended periods of time. The corsac fox is an opportunistic forager and hunter. Its diet varies throughout its range, but consists foremost of small and medium-sized vertebrates, insects and small rodents, such as voles, gerbils, jerboas, hamsters, and ground squirrels. It also feeds opportunistically on larger prey including hares and pikas. It scavenges for carrion and human refuse as well. Although predominantly carnivorous, it occasionally eats fruit and other vegetation, especially during winter when availability of animal prey is low. Natural predators of the corsac fox include gray wolf, Eurasian eagle-owl, eagles, and (rarely, for pups) the upland buzzard. Golden eagles are major predators, with 38% of remains found belonging to the corsac fox at a golden eagle nest in Mongolia. The Corsac fox is a nocturnal and nomadic hunter of the steppes. It does not have a defended territory, and unlike some foxes, sometimes forms packs. Diurnal activity is more common at times when kits need to be fed and when food is scarce, as during the winter. Because it cannot hunt in deep snow, it either shelters in dens during harsh weather, or, in the northern parts of its range, it migrates up to south in the winter. It has been reported to follow herds of local antelope, relying on them to compress the snow as they pass. It digs its own dens, which are generally shallow, but also takes over the burrows of other animals, such as marmots, ground squirrels, or badgers. Dens may have several entrances, but are usually less than deep. The burrow is shared between the social packs, with several dens and connecting holes, which resemble "corsac cities". They are excellent climbers, but are rather slow runners and could be caught easily by a dog. While they are reported to be nocturnal in the wild, in captivity they are very active during the day. Reproduction The mating season starts in January and ends in March. Males will initially fight for access to females, but eventually establish a monogamous bond, and assist in the raising of their young. The mother initially 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, two to six young are born after