Black-tailed Prairie Dog. The black-tailed prairie dog became a candidate for listing in 2000. In August 2004, the FWS determined the black-tailed prairie dog was no longer warranted candidate status. However, the black-tailed prairie dog is classified as a sensitive species by both Region 2 of the U.S. Forest Service and the Wyoming State Office of the Bureau of Land Management and is still considered rare throughout its range. The Wyoming Game and Fish Department (2010) identifies the black-tailed prairie dog on its list of Species of Greatest Conservation Need because populations have declined and its habitat is vulnerable. However, there is no identified ongoing significant habitat loss in Wyoming. The black-tailed prairie dog is designated as vulnerable by the Committee on the Status of Endangered Wildlife in Canada and threatened by the Lista de las Especies Amerzadas, the official threatened and endangered species list of the Mexican Government. In-depth information regarding the background and status of the black-tailed prairie dog is presented in the FWS’s finding for the resubmitted petition to list the black-tailed prairie dog as threatened103 and the subsequent 90-day finding104. Information provided below is primarily from the petition and the FWS’s finding.
Black-tailed Prairie Dog. Natural History The black-tailed prairie dog is one of five species of prairie dog, all of which occur only in North America. It is a small rodent that exhibits a colonial lifestyle, living in xxxxxx systems within generally large, dense colonies. This lifestyle may represent the most complex social organization of all rodents and likely offers an effective defense mechanism against predators and increases reproductive success, though facilitating the transmission of disease. Black-tailed prairie dogs are associated with grasslands and shrub-grasslands and, in Wyoming, appear most abundant on shortgrass prairies. Towns, or colonies, are loosely defined as aggregations of prairie dogs, while colonies are further organized into “coteries” made up of 2 to 40 members105. Coterie members defend their group territory against intrusion by members of adjacent coteries. Xxxxxxx et al. (1993) define prairie dog complexes as prairie dog colonies within a 4.3 mile (7.0 km) radius of other prairie dog colonies. Typical dispersal between established colonies is 3 miles (4.8 km) or less. Black- tailed prairie dog densities vary depending upon season, region, and climatic conditions, but typically range from 2 to 18 individuals per acre (0.8 to 7.2 individuals per hectare). Black-tailed prairie dogs are active above ground year round. Prairie dogs consume both grasses and forbs, and a majority of their diet may include plant species having value as livestock forage, such as western wheatgrass (Pascopyrum smithii), blue grama (Bouteloua gracilis), and needle-and-thread (Hesperostipa comata). Utilization of vegetation by prairie dogs in newly established colonies has been estimated at 18 to 37 percent. Most utilization affects grasses and can reach as high as 80 percent by mid-August. In some cases utilization may approach 100 percent. 103 69 FR 51217, August 18, 2004 104 73 FR 73211-73219, December 2, 2008 105 Xxxxxxxx (2006) A female may produce up to 20 offspring during its lifetime, producing a single litter of 4 to 5 pups per year over a lifetime of 3 to 4 years. While not prolific in comparison to many other rodents, the species is capable of rapid population increases subsequent to substantial reductions. Black-tailed prairie dogs are very sensitive to plague, and mortality frequently reaches 100 percent106. Two patterns of die-offs are typically described for black-tailed prairie dogs: 1) a rapid and nearly 100 percent die-off with incomplete recovery, such as has o...
