Despite increasing public concern over the plight of the prairie dog, the future of this animal, as well as prairie-dog ecosystems, remains precarious and uncertain.
At the recent Prairie Dog Summit, held by the Prairie Dog Coalition in Denver, wildlife protection advocates, government wildlife biologists, and university researchers presented evidence of prairie dog population declines, the factors responsible for these declines, and potential avenues by which we might effectively recover prairie dogs and the ecosystems they help shape.
No ESA Relief in Sight for Black- and White-Tailed Prairie Dogs
Speakers at the summit cited a history of poisoning campaigns, unrelenting habitat loss, disease, and recreational shooting as factors that have imperiled all five species of prairie dogs found in North America. The Mexican prairie dog is already federally protected as "endangered" under the Endangered Species Act (ESA); the Utah prairie dog is "threatened" under the ESA; black-tailed and white-tailed prairie dogs have both been petitioned for listing under the ESA; and Gunnison's prairie dogs face threats similar to those of the other species.
The black-tailed prairie dog in particular has been driven from more than 98% of its historical range. Plague, an introduced disease to which prairie dogs have no resistance, may rival poisoning and habitat loss as a serious threat to the black-tailed prairie dog's continued survival. Plague is also a threat to most other prairie dog species and to associated prairie and grassland species such as the black-footed ferret, which is absolutely dependent upon large clusters of prairie dog colonies, sometimes called "complexes."
In response to conservationists' petitions to list the black-tailed prairie dog, the U.S. Fish and Wildlife Service (FWS) determined in February 2000 that the black-tailed prairie dog warranted protection as a threatened species under the ESA. However, the FWS refused to list the black-tailed prairie dog, claiming that its resources were needed to address higher priority ESA actions.
The mere threat of placing black-tailed prairie dogs on the threatened list was enough for the 11 western states in the animal's historic range. Hoping to keep control in their own hands—and away from federal ESA protections—the states initiated management plans for an animal that they perceive largely as an agricultural pest and, especially in Colorado, an obstacle to urban development.
The FWS has not yet responded to the white-tailed prairie dog listing petition, which was submitted over a year ago. The Daily Threats to Prairie Dogs
Recreational shooters, also called "varmint hunters," shoot millions of prairie dogs each year throughout the western states. State wildlife agencies estimate that between 170,000 to 1.2 million prairie dogs are shot annually in Colorado and South Dakota. And since they are widely viewed as pests, prairie dogs are also frequently killed with poisons on private, public, and tribal lands.
Illegal poisoning is also a problem. This was illustrated recently when a Michigan retailer pled guilty in U.S. District Court for violating the Federal Insecticide, Fungicide and Rodenticide Act by selling a product called "Kritter Killer," which contains the rodenticide perchloroethylene. The Environmental Protection Agency had earlier banned the sale and use of perchloroethylene, a suspected carcinogen.
Further, prairie dogs are increasingly subjected to poisoning and habitat loss in the name of urban development. For example, a minor public uproar occurred in 2001 when a developer in Aurora, Colorado poisoned a colony of prairie dogs to make room for a strip mall. While an individual incident like this occasionally attracts media attention, it is not an isolated act. The reckless destruction of prairie dogs—and, consequently, the many species that depend upon them—happens frequently.
Poisoning and habitat loss can have other consequences for prairie dogs: It may make it difficult for a colony to recover from plague outbreaks. After all, a prairie dog population that's already ravaged by poisonings, shootings and habitat loss may not have the ability to recover from a plague outbreak.
The plague alone is already a serious problem for prairie dogs. Sylvatic plague (caused by the bacterium Yersinia pestis) was introduced into the United States at several ports around 1900. Perhaps because plague has occurred in the U.S. only recently, prairie dogs do not have any resistance to the disease. Plague is especially devastating to black-tailed prairie dogs because they are highly social and tend to spread the disease rapidly within a colony, often with nearly 100% mortality.
These daily threats to prairie dogs are particularly significant because, despite their reputation, the animals are not prolific breeders. Females are only capable of producing, at most, one litter per year, with an average of three pups per litter. Fewer than 60% of young prairie dogs survive their first year. Natural causes of death, other than disease, include infanticide and predation. Infanticide, typically committed by other adult females or young males, resulted in the reduction or elimination of 39% of litters in one study. In urban and suburban areas, where development packs prairie dogs into smaller areas, infanticide may be more prevalent.
Not Vermin: Misinformation about Prairie Dogs
While a handful of progressive ranchers and landowners have decided not to poison the prairie dogs on their land—and apparently have experienced no detrimental effects to their livelihood as a result—attitudes toward prairie dogs and other species traditionally perceived as "vermin" change slowly. Many people remain firmly—and loudly—convinced that the only good prairie dog is a dead prairie dog.
Many people believe that prairie dogs compete with cattle for forage and that livestock are likely to break their legs by stepping into prairie dog burrows. Although prairie dog foraging reduces plant biomass to a small degree, it also increases the nutritional quality of plants, simply because of the way plants have evolved to respond to herbivory. Furthermore, the diet of prairie dogs overlaps only minimally with that of domestic cattle. In fact, several researchers have found that both cattle and wild ungulates (e.g. bison, pronghorn) actually prefer to graze on prairie dog towns.
In regard to cattle and burrows, little or no evidence exists to suggest that livestock are injured more frequently on prairie dog towns than elsewhere. State Management Plans
Because the black-tailed prairie dog is a candidate for listing under the ESA, the 11 states within the black-tailed prairie dog's historic range are in the process of drafting management plans for this species. However, most states clearly indicate that their purpose in drafting a plan is to avoid the federal listing of the black-tailed prairie dog and thus to keep prairie dog management in their own hands.
This perspective is in contrast to that of most biologists and conservationists who place the greatest emphasis on the recovery and protection of prairie dogs and prairie dog ecosystems for the sake of biodiversity on our prairies and grasslands.
Despite the many threats to prairie dogs, the proposed state black-tailed prairie dog management plans do not include strong enough protections. Plans typically would allow the continued poisoning of entire colonies on public and/or private lands.
Some state plans propose seasonal shooting closures, while others do not. But for several reasons, even seasonal shooting closures are not likely to go far enough in protecting populations. First, where they have been proposed, closures apply to public lands only, even when the most shooting occurs on private lands. Second, there are (and would continue to be) no "bag" limits imposed upon prairie dog shooters. Third, a seasonal closure is likely to merely shift shooting pressure temporally, such that it occurs more often in late summer or fall.
State plans do include some conservation measures such as landowner incentives to allow prairie dogs to remain on private property relatively unmolested. However, without substantial restrictions on shootings and poisonings, any positive effect of the incentive program would likely be outweighed by the continued eradication of prairie dogs.
Unfortunately, states may not even implement the minimal protections suggested by their own working groups in the management plans. So far, the Arizona and Wyoming wildlife commissions have rejected their respective black-tailed prairie dog management plans, apparently because they require too many conservation measures. The other plans remain simply words on paper and, in reality, mean little or nothing for prairie dogs.
You Can Help
The HSUS is one of several member organizations of the Prairie Dog Coalition. The coalition works to recover and protect prairie dogs and prairie dog ecosystems. To find out more about the Prairie Dog Coalition or to sign a petition on behalf of prairie dog protection or even to learn how you can volunteer, go to the coalition's web site.
