Vulpes velox velox (Say)
Description: The swift fox is the smallest member of the family Canidae in Kansas, and in general form it looks like a miniature coyote. It can be distinguished from other members of its family by: 1) white to pale buff underparts and throat, 2) black patches on the sides of the buffy yellow muzzle; deeper yellow brown on the lower neck, front and hind limbs, and the back of the ears, 3) long, buffy-gray fur on the back with a mixture of gray-brown fur beneath it, creating a frosted appearance, and 4) long and well-furred tail with a black tip.
Size: Adults may attain the following dimensions: total length 783-812 mm; tail 269-279 mm; hind foot 120-124 mm; ear 63-64 mm; weight 2.3-2.4 kilograms.
Range and Habitat: The swift fox was once distributed throughout the western half of the state, but may have been extirpated in Kansas by the late 1800's. It has recently reappeared in Kansas, but remains uncommon. It is an inhabitant of open prairie, and seems to be equally abundant on both flat and hilly terrain, but prefers soils that are well-drained and friable.
Reproduction: Following pairing, breeding takes place in late December or early January. Gestation is about fifty days after which three to six pups (average five) are born in a grass-lined burrow. The young are born blind and with their ears closed. They are about 160 mm long at birth and covered with a sparse brown fur. Their eyes open at 10 to 15 days and they are weaned at 42-49 days. The pups stay near the den until mid-June after which they join their parents in hunting. By mid-July they are nearly full grown, but remain in the family groups until August or early September. The young are probably capable of breeding in their first year.
| Swift foxes are mainly nocturnal in their activities, and may diurnal activity is centered around the den site. During the winter they may be found sunning during midday, but in the summer they will be observed only during morning and early evening hours. A social unit consists of a male, one or two females, and their offspring. After the young disperse, the parents remain together and are thought to pair for life, but this is unconfirmed.
Dens are construct in friable, well-drained soils and are used throughout the year. Temporary dens usually have one or two openings, a single main tunnel,and possibly a side tunnel. Permanent burrows usually have two or more openings (up to nine), tend to have many connecting tunnels, and one or more main chambers. The burrows may be one to one and half meters below the surface. The size of swift foxes' home range appears uncertain and probably varies with the productivity of the habitat.
Adult swift fox at a den.
Food: The diet varies seasonally with small mammals making up the major bulk of the diet. Rabbits and hares are most common in the spring, but other small mammals such as kangaroo rats, pocket mice, deer mice, cotton rats, and ground squirrels are important diet items in the autumn. Large quantities of insects are also eaten.
Remarks: The cause for the severe population decline of the swift fox seems to have been the poisoning of carrion to reduce wolf, and later, coyote populations; swift foxes are presumably more susceptible to this control method. Coyotes, and perhaps formerly wolves, are suspected natural predators of swift foxes. Maximum longevity for this small mammal is ten years or more, but most wild swift foxes probably do not live longer than three to four year.
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