Utah prairie dog

Species of rodent

The Utah prairie dog (Cynomys parvidens) is the smallest species of prairie dog endemic to the south central steppes of the American state of Utah. The species is listed in the IUCN Red List of Threatened Species with a status of Endangered. Because of this, it is a protected species; the prairie dog faces various threats the most dangerous being habitat loss and disease.

The fur of Utah prairie dogs is multicolored, which consists of black, brown, and dark brown at the tip. Their faces have dark brown cheeks and whitish tone around their chins and mouth. Utah prairie dogs also have distinctly clay colored proximal tail parts and dorsum, as well as dark eyebrows. In terms of taxonomy, there are two subgenera of prairie dogs: "black tailed" prairie dogs and "white tailed" prairie dogs. Utah prairie dogs are a member of the latter of the two groups and the subgenus Leucrossuromys. Utah prairie dogs may have been part of the interbreeding species of white tailed prairie dogs but their differences are a result of what is known as allopatric speciation – separation of a species by physiographic and ecological barriers.

The total body length of typical adult Utah prairie dogs ranges from with of tail. Utah prairie dogs exhibit sexual dimorphism; males are 27% bigger than females, although the ratio varies by season. Their body weights can span from in the spring, and in the summer for males.

Utah prairie dogs are only found in the southern part of Utah. They have the most constrained range when compared to the other four species of prairie dogs in the United States (Gunnison's prairie dog, Mexican prairie dog, the white tailed prairie dog, and the black tailed prairie dog) none of which overlap geographic territories. Today the Utah prairie dog is only found in the central and southwestern part of Utah in Beaver, Garfield, Iron, Kane, Piute, Sevier, and Wayne Counties. However, it was recorded that Utah prairie dogs existed as far north as Nephi, as far south as the pine fir forests of Bryce Canyon National Park, and Aquarius Plateau to the east in 1920, but the number declined from the 1920s to 1970s by 87%. This reduction was thought to be a result of human settlers who caused overgrazing of soil, and thus catalyzed the invasion of shrub to the grass land. Agricultural properties often provide Utah prairie dogs with suitable habitats, but when populations get too dense, outbreaks of plagues become common (of which fleas are the typical vectors) and can demolish entire colonies. They highly prefer grasses and forbs but they also do consume flowers on shrubs. Utah prairie dogs choose only a few species of grasses that are native to their surrounding soil. Eating green vegetation and forbs of high quality allows them to obtain large quantities of protein and energy, which is critical for activities such as lactation and hibernation. The size of litters directly correlate with maternal body mass. However, approximately twenty percent of the litter may be eradicated due to males cannibalizing juvenile Utah prairie dogs. The breeding occurs generally from mid March through early April.

The primary predators of Utah prairie dogs include badgers (Taxidea taxis), many species of raptors (Aquila chrysaetos, Buteo spp. ), coyotes (Canis latrans), snakes (Pituophus spp., Crotalus spp. ), and long tailed weasels (Mustela frenata). However, predators do not pose a significant threat to the numbers of prairie dogs in well established colonies. They are protected under the 1973 Endangered Species Act (ESA). In 1920 there were approximately 95,000 Utah prairie dogs and over the span of around 50 years, the population was decimated by an estimated 50%. Reports have shown that this was a result of population control programs that were instituted in the 1920s, unregulated shooting, and poisoning. Other factors that contributed to this drastic reduction include diseases, increased aridity, overgrazing of habitats and habitat loss, epizootic infections, cultivated agriculture, invasive plant species, climate change, poaching, the exploration and development of energy resources, off highway vehicle recreation, fire management, and urban development. In 1972, studies estimated a population of 3,300 Utah prairie dogs in 37 colonies. Studies by the Utah Division of Wildlife Resources in spring 2004 reported 4,022 Utah prairie dogs, a number believed to reflect half of the total current population. The Utah prairie dog can do significant damage to farms by digging holes and eating crops, drawing the ire of Utah farmers, who have used poison liberally to destroy the animals. This is a major reason for the population decline, though there are other factors, such as "land development, deteriorating rangeland health, the encroachment of woody vegetation, sylvatic plague, [bubonic plague], and drought."

Conservation efforts include encouraging landowners to improve the health of their rangelands, and compensating farmers who set aside areas the prairie dogs may use. The United States Fish and Wildlife Service, along with the Utah Ecological Services Field Office, have published recovery plans with varying proposed strategies to protect Utah prairie dog populations. Some descriptions of such plans that have yet to be implemented include monitoring and developing a database for plague incidents, developing methods of natural disturbance responses (such as fire or drought), creating a volunteer based stewardship program with the intention of educating and informing citizens, and establishing educational kiosks and Utah prairie dog viewing sites for the public. Additional conservation plans that are ongoing include those in which private landowners who contractually agree to habitat management or restoration receive financial and market based incentives, endowment funds for the management and administration of protected properties are established, vegetation treatment in tactical areas are implemented, and strategies to further funding for outreach programs are developed. Many of these expensive recovery actions are anticipated to generate full recovery of the Utah prairie dog species by the decade of 2040, if properly adhered to proposed schedules.