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 .

(US Fish and Wildlife Service 1991).

Biogeographic Regions: nearctic (Native )

endemic to a single state or province

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (1000-5000 square km (about 400-2000 square miles)) The range is restricted to an area of about 1,850 square kilometers in southern Utah. Prior to control programs, the range reportedly extended from Pine and Buckskin valleys in Beaver and Iron counties (perhaps west to Modena in Iron County), north to at least Salina Canyon and near Gunnison in Sevier County (possibly to Nephi), south to Bryce Canyon National Park, and east to the foothills of the Aquarius Plateau (Collier 1974, Pizzimenti and Collier 1975, McDonald 1997). More recently, this species occurred in substantial populations in only three areas: the Awapa Plateau, along the east fork of the Sevier River, and in eastern Iron County; the grass and Sevier river valleys, plus three small, widely separated mountain valleys have small populations (Collier 1974, Pizzimenti and Collier 1975). The species is scarce or absent in the Aquarius Plateau, Fremont and Paria valleys, and Salina Canyon (Collier 1974, Pizzimenti and Collier 1975).

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 below 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 60 mm and the hind foot is 55 to 66 mm long. The ears are 12 to 16 mm long. (Parker 1990, US Fish and Wildlife Service 1991).

Length: 39 cm

Dorsal pelage of Cynomys leucurus is pinkish buff mixed with buff; Cynomys gunnisoni has grayish hairs in center of tail; C. ludovicianus has a black-tipped tail (Whitaker 1996).

• Terrestrial

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. (US Fish and Wildlife Service 1991).

Terrestrial Biomes: savanna or grassland

Comments: Habitat consists of grasslands, in level mountain valleys, in areas with deep well-drained soil and vegetation that prairie dogs can see over or through. Prairie dogs dig underground burrow systems, in which the young are born.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

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. (US Fish and Wildlife Service 1991).

Comments: Feeds primarily on grasses, alfalfa, leafy aster, European glorybind, wild buckwheats in seed, flowers and seeds of shrubs, and insects when available; also may consume cattle feces; generally prefers flowers and seeds over leaves.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 21 - 80

Comments: On a broad scale, USFWS (1991) mapped about two dozen subpopulations (distinct patches of occupied habitat).

2500 - 10,000 individuals

Comments: Counts by the Utah Division of Wildlife Resources in 2004 yielded a population estimate of approximately 8,000 adults (USFWS, http://mountain-prairie.fws.gov/species/mammals/utprairiedog/).

Population densities are extremely variable, ranging from a mean of less than 2.5/ha to more than 74/ha (Pizzimenti and Collier 1975). Lives in colonies ("towns"). Colony structure is dynamic in size and location; social units within colony comprise a dominant male, several females, and the young of the past 2 years (Matthews and Moseley 1990).

Survivorship in first year less than 50%; only 30% remain alive at the end of their second year (Hoogland 2001).

Comments: Inactive and torpid in severe winter conditions. Adults emerge and begin foraging from mid-March to early April, enter dormancy mid-July to mid-August; juveniles enter dormancy from early October to mid-November; low elevation colonies (below 7000 ft) generally are two weeks earlier than higher elevation colonies (Spahr et al. 1991).

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. (US FIsh and Wildlife Service 1991).

Reproduce slowly, relative to other rodents (Hoogland 2001). Females produce only one litter per year, but the probability of weaning a litter each year is only 67% (Hoogland 2001). Although all females copulate as yearlings, only 49% of males do so (Hoogland 2001). For females that wean offsptring, mean litter size at first emergence from the nursery burrow is 3.88 (Hoogland 2001).

Mating occurs in March or April. Gestation lasts about 1 month. Young are born in late April or early May. Litter size is 2-10 (average 3-5); female produces one litter per year. Young emerge above ground at 6 weeks (late May to early June), weaned in about 7 weeks, first breed at about 2 years.

Cynomys parivdens was previously listed as endangered. The Utah prairie dog had become endangered due to several factors. These include diseases, poisoning, droughts, and habitat alterations for cultivation and grazing. Plague outbreaks occur when a colony is overpopulated and there is increased stress on the individuals. From 1972 to 1989 a transplant program was initiated to move Cynomys parvidens from private agricultural areas to pubilic land sites. This program proved successful and the species was reclassified to threatened in May, 1984. (US Fish and Wildlife Service 1991).

IUCN Red List of Threatened Species: endangered

United States

Rounded National Status Rank: N1 - Critically Imperiled

Rounded Global Status Rank: G1 - Critically Imperiled

Reasons: Small range in southern Utah; fewer than 20 "populations" with a reasonable chance for long-term survival; threatened by habitat loss and degradation and plague outbreaks; difficult to protect habitat.

Other Considerations: Dynamic nature of colony size and location - grow from center, die off and increase at peripheries.

Global Long Term Trend: Decline of >90%

Comments: Population in 1920 (before control programs) has been estimated at 95,000 (USFWS 1990). Currently the adult population size is thought to be fewer than 10,000. Historical area of occupancy has declined from about 1,800 square kilometers historically to only about 28 square kilometers today.

Degree of Threat: A : Very threatened throughout its range communities directly exploited or their composition and structure irreversibly threatened by man-made forces, including exotic species

Comments: The major historical decline was primarily a result of intensive poisoning efforts. For example, in 1971, poisoning "annihilated" one of the few remaining large colonies (near Loa, Wayne County) (Pizzimenti and Collier 1975). In 1972, the largest colony (Enoch, Iron County) was reduced from more than 1,000 individuals to fewer than 50, apparently from poisoning (Pizzimenti and Collier 1975).

Recent threats include habitat destruction resulting from residential and agricultural development on private lands, deliberate (illegal) poisoning and shooting by ranchers and farmers concerned about agricultural damage, and plague outbreaks (Hoogland et al. 2004). Plague has caused major declines in various populations over the past several decades. Grasslands are becoming dominated by sagebrush due to livestock grazing (K. McDonald, pers. comm., 1995); shrubby habitats provide poor conditions for prairie dogs. Drought may reduce prairie dog food resources and cause population declines in colonies on drier sites. See Iron County Commission and Utah Division of Wildlife Resources (1998) for further information and references.

Management Requirements: State wildlife officials are permitted to control populations in order to prevent excessive damage to agriculture; removed individuals are used in reintroduction program. See Coffeen and Pederson (in Oldemeyer et al. 1993) for information on transplant techniques and site selection criteria.

A strategic management plan has been completed by the state of Utah (USFWS 1990). A habitat conservation plan has been developed for Iron County (Iron County Commission and Utah Division of Wildlife Resources 1998).

Livestock grazing may improve habitat by producing shorter vegetation and encouraging regrowth, but overgrazing can be detrimental by reducing the production of cool-season grasses, such as blue grama, by causing loss of moist swales or small meadows through gullying, and by encouraging the growth of tall shrubs (Spahr et al. 1991).

Infusion of burrows with Pyraperm (an insecticide-dust) kills fleas and immediately halts the spread of plague within colonies (Hoogland et al. 2004).

Management Research Needs: See Miller et al. (in Oldemeyer et al. 1993) for a list of questions for management and research, related to ferret reintroduction, in priority order in each category of disease, habitat management, population dynamics, and public relations.

Biological Research Needs: Research needs include: determine causes of high rate of crashes of local populations; determine rangeland revegetation and grazing practices that will result in improved persistence of translocated populations; determine genetic consequences of high rates of population crashes and how this affects the spatial arrangement of translocation sites and numerical goals for population recovery (Utah Prairie Dog Recovery Implementation Team 1997).

Global Protection: Few (1-3) occurrences appropriately protected and managed

Comments: One colony is protected in Bryce Canyon National Park. As of 2004, despite public land efforts at establishing new Utah prairie dog colonies and supplementing existing ones, approximately 68% of Utah prairie dogs still occur on private and other nonfederal lands.

Needs: See USFWS (1991) and Utah Prairie Dog Recovery Implementation Team (1997).

Utah prairie dogs can cause serious crop and equipment damage in agricultural areas. (US Fish and Wildlife Service 1991).

Stewardship Overview: Actions Needed (Recovery Plan, USFWS 1991): 1. Determine historical range and species distribution. 2. Continually update information on present populations and distributions. 3. Determine what factors influence the viability of prairie dog colonies. 4. Select management and transplant sites. 5. Conduct transplant program. 6. Monitor transplanted colonies. 7. Ensure protection of prairie dogs and their habitat on both existing and transplant sites on public and private lands. 8. Manage prairie dog colonies by developing and implementing sitespecific management plans for each colony or transplant site. 9. Conduct an information and education program.

See Utah Prairie Dog Recovery Implementation Team (1997) for an update.

Comments: Cynomys parvidens has been regarded as a subspecies of Cynomys leucurus by some authors. Thorington and Hoffmann (in Wilson and Reeder 2005) recognized the two taxa as distinct species.