While prairie dogs once were ubiquitous in the western United States, sylvatic plague infestations and habitat fragmentation have reduced populations to less than five percent of their historical distribution. Stakeholders in the shortgrass steppe ecosystem of Colorado have conflicting views on the critters, but the Shortgrass Steppe LTER (SGS) is providing research results to clarify concepts and enable desicion making.
The National Wildlife Federation petitioned to have the prairie dog listed as "threatened" under the Endangered Species Act, but the U. S. Fish and Wildlife Service found the species "warranted, but precluded" for listing. The status of the species will be reviewed yearly, and prairie dogs could become federally protected if conservation efforts by state and local governments are not successful.
While there seems to be a consensus among policy-makers, farmers, ranchers, developers, and biologists that the prairie dog should be kept off the endangered species list, the role and the fate of the critters remains the major question. Some view the prairie dog as a keystone species, integral to the viability of the shortgrass ecosystem. Others think of prairie dogs as vermin, incompatible with farming, ranching, and urban development.
Conservation efforts are further complicated by the presence of the sylvatic plague. Little is known about how the plague moves from one population to another, how it affects the genetics of prairie dog metapopulations, or how it can impact humans and domestic animals. Once a colony is infected, decimation is fast and usually complete. SGS LTER researchers are working to provide scientific information about the species. Their results are effecting policy decisions, conservation practices, and historical misconceptions about the black-tailed prairie dog.
James Detling and his graduate students have found that while prairie dogs appear to reduce cover and biomass of graminoids, their herbivory may result in an increase of forbs, shrubs, and overall forage quality on prairie dog towns. LTER graduate student J. P. Farrar is analyzing plant samples from colonies in Texas, Colorado, and Montana to determine the effects of prairie dogs on plant biomass and nitrogen content. Graduate student Debra Guenther recently completed research that suggests that cows do not avoid grazing on prairie dog towns. These studies challenge the notion that the presence of a prairie dog town precludes the use of the land by cattle. If prairie dogs and ranching are not incompatible, ranchers may be less likely to contribute to population decline by exterminating colonies found on their property. Farmers and ranchers are already helping to conserve the mountain plover (Eupoda montana) and may indeed be receptive to active conservation efforts for prairie dogs, especially if incentives are offered.
Prairie dogs may be a keystone species in the shortgrass ecosystem. Graduate student Jeanine Junell is examining arthropod communities on and off prairie dog towns in the Pawnee National Grasslands. The Shortgrass Steppe LTER Field Crew has conducted animal surveys and vegetation surveys to compare species composition on and off prairie dog towns. Burrowing owls (Athene cunicularia) frequently hunt and nest on towns. Recreational shooting of prairie dogs may be contributing to the decline of the owl species by negatively influencing nesting success, according to LTER student Jason Woodard, and the Colorado Division of Wildlife will prohibit shooting of prairie dogs on public lands as of September 2001. Prairie dog colonies are considered parts of a larger metapopulation in which local extinction due to plague and subsequent recolonization are common. Graduate students of Dr. Beatrice Van Horne and Dr. Michael Antolin have been using allozyme, minisatellite and microsatellite markers to answer questions about genetic subdivision and dispersal patterns of this highly social species. Genetic information may offer answers to questions such as whether it is imperative to concentrate efforts on preserving large metapopulations and what the prognosis is for small colonies that have been isolated by urban expansion or agriculture. Furthermore, developers often pay to have colonies transplanted, at considerable expense and questionable success. Growing knowledge of social behavior and dispersal tendencies has increased success of colony relocation.
A multi-agency workshop was held February 27th through March 1st to discuss the status of black-tailed prairie dogs in Colorado. The workshop was held in Fort Collins, Colorado and organized by EDAW Inc., a private consulting firm. Among the attendees at the meeting were representatives from the Shortgrass Steppe LTER, the Colorado Division of Wildlife, the U. S. Fish and Wildlife Service, the U.S. Department of Agriculture, the Colorado Farm Bureau, the Colorado Cattleman's Association, and the cities of Fort Collins and Boulder. This workshop was informative, inclusive, and an overall success.
Several salient points were made. Most agencies and individuals do not want to see the prairie dog listed under the Endangered Species Act. Transplantation rather than extermination of colonies is better for public relations, but relocating animals is complicated by the lack of available land, the social nature of the species, and by the complex genetics of metapopulations. Educated guesses are prolific, but nobody really knows how the sylvatic plague will continue to influence prairie dog populations. Most farmers and ranchers have never seen prairie dogs as compatible with their professions, but views are changing and many individuals may be receptive to information and incentives. To be sure, these small mammals are making a large impact on politics and policies in Colorado. Researchers of the Shortgrass Steppe LTER will continue to provide scientific information regarding the ecology and biology of the black-tailed prairie dog.