Cynomys parvidens

Utah prairie dog


Classification

Geographic Range

Nearctic: North America - Southwest area of Utah.

There are three main concentration of colonies: Awapa Plateau, East Fork and the main stem of the Sevier River and eastern Iron County. Cynomys parvidens is the westernmost member of the genus Cynomys.

Physical Characteristics

Utah prairie dogs are the smallest of all prairie dogs. The back is cinnamon in color and the tail is almost all white. The belly is also cinnamon but brighter than the back. The upper lip and chin are white and there are dark brown spots above and be low the eyes. Females have five pairs of mammae. The first upper premolar is more strongly developed than in other Cynomys species and almost equal in size to the second premolar. Total length of the body is 305 to 360 mm. The tail length is 30 to 60mm and the hind foot is 55 to 66 mm long. The ears are 12 to 16 mm long.

Natural History

Food Habits

Utah prairie dogs are mostly herbivorous. They prefer flowers and seeds over grass, however grass is available more often than seasonal flowers and seeds. Young leaves are preferred over old leaves and stems are rarely eaten. Young Utah prairie dogs prefer dead vegetation and cattle feces. Cynomys parvidens eat insects (cicadas) when available.

Reproduction

The gestation period lasts about 30 days and young are born in April. There are between 3 and 4 young per litter. Adult size is reached in October and adults become sexually mature when one year old.

Behavior

Cynomys parvidens are active during the day. They form colonies and dig extensive burrow systems underground. The young begin to appear above ground when they are 5 to 7 weeks old. Males stop coming above ground during August and September with females following a few weeks later. Juveniles continue surface activity for another one to two months before going below ground. Between November and February, Utah prairie dogs remain mostly underground, although they do not become completely dormant in the winter.

Utah prairie dogs use dead vegetation for building nests in the burrows. Their main natural predators are badgers, coyotes, raptors and weasels. These predators probably have more impact on new colonies and expanding colonies than established colonies because the burrow system is less developed.

Habitat

Certain soil and vegetation characteristics must be met in order for Utah prairie dogs to establish a colony in a particular prairie. The area must be well-drained and have soil deep enough for protection against predators and for insulation during the winter. Cynomys parvidens must be able to dig one meter deep without getting wet. The vegetation must be low enough to allow the prairie dogs to scan the environment for predators. The range of Cynomys parividens is restricted by climate, physical, and biological barriers. The western region has higher temperatures and a drier climate and the tall grass restricts viewing of the surroundings. Mountains and deserts to the east, west and south may be impassible. Competiton with Uinta ground squirrel (Spermophilus armatus) probably limits expansion as well.

Other Comments

Utah prairie dogs shed twice a year.