Utah Prairie Dog

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Utah Prairie Dog

Cynomys parvidens

StatusThreatened
ListedJune 4, 1973 Endangered
ReclassifiedMay 29, 1984 Threatened
FamilySciuridae
DescriptionYellow-brown rodent with a short white-tipped tail and black "eyebrows."
HabitatSandy soil in scrubby areas.
FoodSeeds, leaves, new plant growth.
ReproductionLitter of 2-10.
ThreatsHabitat reduction, competition with ranchers and farmers, low numbers.
RangeUtah

Description

The Utah prairie dog, Cynomys parvidens, is a large burrowing rodent with short legs, a head and body length of about 12 in (30 cm), and a tail length of about 3.5 in (8.9 cm). The species is distinguished by its short white-tipped tail and black "eyebrows." Its upper body is cinnamon or clay colored with buff-and black-tipped hairs, which are slightly darker on the rump. The mouth and chin are white, and the underparts are cinnamon to pale buff.

This species was first described in 1905 from specimens collected at Buckskin Valley, located in Iron County, Utah. Some biologists consider it a subspecies of Cynomys leucurus.

Behavior

The Utah prairie dog, like other prairie dogs, lives in organized colonies called prairie-dog towns, sometimes consisting of as many as several thousand animals. Towns are divided into wards, which are in turn divided into coteries. Each coterie contains a dominant male, along with several females, and the young of the past two years. Gestation is 28-32 days and litter size ranges from 2-10, born in the spring. Pups' eyes open in 33-37 days, and they are weaned after about seven weeks. The mother then digs a new burrow, or moves to an empty one, and parental care ceases. The young remain at their natal burrow for a few weeks, then leave to singly occupy empty burrows within the colony. The young become sexually mature at one year. Some females may breed at one year of age. Burrows, about 6 in (15 cm) in diameter, go straight down for about 10-16.5 ft (3-5 m), then branch into two or three horizontal tunnels containing grass nests. Earth around the burrow entrance is mounded into a cone shape to deflect rain-water. During the severe period of winter, prairie dogs hibernate. They feed on herbs and grasses.

Habitat

Prairie dogs inhabit grassland prairies of the Central Plains. The species is commonly associated with open rangeland, and with agricultural or abandoned farmland producing crops such as alfalfa and oats. Colonies seem to prefer moist ground at elevations of 7,220 ft (2,200 m) or lower, with some water present during part of the year. Ideal habitat consists of short grass interspersed with bare ground and patches of forbs which can be found in grassy upland and mountain areas.

Distribution

Other members of the genus Cynomys are found throughout Wyoming and in portions of Colorado, Utah, New Mexico, and Arizona. The Utah prairie dog is found only in south-central Utah. In the 1920s the total Utah prairie dog population was estimated at about 95,000. This species is found in reduced numbers throughout its historic range. The only significant populations are found in Garfield, Iron, and Wayne counties; with smaller populations in Kane, Piute, Sevier and Beaver Counties in Utah. There is evidence of "trace activities" in an additional 54 areas (22 hectares) in Garfield, Iron, Sevier, and Wayne Counties. Approximately 54% of the present known populations are located on private agricultural lands. Some colonies are located on land managed by the National Park Service (Bryce Canyon National Park), the U. S. Bureau of Land Management (Richfield and Cedar City Districts), and the U. S. Forest Service.

Threats

All species of prairie dogs have suffered from competition with ranchers and farmers for grazing territories. Prairie dogs became a target for elimination beginning with human settlement of the West. Farmers and ranchers still commonly poison the animals. Other prairie dog predators are coyotes, foxes, badgers, hawks, and eagles.

The competition with ranchers and farmers is not over for the Utah prairie dog. Beginning in the early 1970s the downward population trend was halted, and prairie dog numbers began to increase. Some areas saw a sixfold increase in the population between 1976 and 1984. Responding to this changing population trend, in May 1984 the U. S. Fish and Wildlife Service (FWS) reclassified the status of the Utah prairie dog from endangered to threatened. In addition, the FWS established a special regulation that allows state officials to control Utah prairie dog numbers in order to prevent excessive damage to local agriculture. Each year between June and January, when new births swell the prairie dog population, a maximum of 5,000 animals may be taken under the supervision of state wildlife officials. State officials argued that if such control measures were not allowed they would be unable to prevent the illegal poisoning of large numbers of the animals. Under the regulation, Utah wildlife officials must monitor and census Utah prairie dog numbers and report them to the FWS.

Conservation and Recovery

A transplant program managed by the Utah Division of Wildlife Resources has been very successful. A positive trend in population numbers has occurred since 1976. Another indication of the success of the recovery efforts has been the decrease in the percentage of the species on private land, from a high of 83% in 1980 to a low of 53.8% in 1986. The 1992 recovery plan for the Utah prairie dog has as its primary objective the delisting of the species by establishing and maintaining it as a self-sustaining, viable unit with retention of 90% of its genetic diversity. FWS believes this can be accomplished by determining the historical range and species distribution; continually updating information on present populations and distribution; determining the influential factors in colony viability; selecting management and transplant sites; conducting transplant programs; monitoring transplanted colonies; ensuring the protection of the species and its habitat on both existing and transplant sites on public and private lands; managing colonies by developing and implementing site-specific management plans for each colony or transplant site; and conducting an information and education program.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
P.O. Box 25486
Denver Federal Center
Denver, Colorado 80225
http://www.r6.fws.gov/

References

Allen, J. A. 1905. "Cynomys parvidens. " Science Bulletin, Museum of the Brooklyn Institute of Arts and Sciences 1: 119.

Hall, E. R., and K. R. Kelson. 1959. Mammals of North America. Ronald Press, New York.

Nowak, Ronald M., ed. 1991. Walker's Mammals of the World. Johns Hopkins Press, Baltimore.

U. S. Fish and Wildlife Service. 1991. "Utah Prairie Dog Recovery Plan." U. S. Fish and Wildlife Service, Denver.