Gaining Ground

Prairie dogs lay the groundwork for endangered species restoration in Thunder Basin National Grassland

I recently joined managers from the Medicine Bow National Forest, the group of folks who oversee management of the Thunder Basin National Grassland, and a crew of young hands from the Montana Conservation Corps (MCC), on the plains of eastern Wyoming. The managers were celebrating a day unchained from their desks, pitching in with their own field biologists to complete some of the work that goes on daily in keeping the lands managed by the U.S. Forest Service healthy and productive habitats for wildlife. The MCC crew was hired by Defenders, World Wildlife Fund, and the Humane Society of the U.S. specifically for the purpose at hand, which today was “flea control.”

Some species of fleas carry the plague (Yersinia pestis) bacteria, the same plague that gained fame in the Middle Ages by wiping out about a third of the entire population of Europe. Today, plague has a less dramatic effect on human populations — there are only about seven or eight human plague cases a year in the U.S., easily treated if caught in time — but the disease has taken on a much more significant role in decimating North American wildlife populations. Its deadly effects are due to a lack of immunity in many wildlife species to this disease that arrived on our continent very recently, around 1900.

Prairie dogs are well known victims of plague, dying by the tens of thousands each year. Scientists believe plague may be implicated in the deaths of other wildlife as well, including species like mountain lions, pikas and highly endangered black-footed ferrets. For Defenders, the key to ensuring that black-footed ferrets are recovered is twofold. First it’s critical that ferrets have a fighting chance to beat exposure to plague, and second, it is important that the ferrets’ primary food source — the prairie dogs — are also able to survive. Currently, the main way to manage plague outbreaks is to keep flea populations low. Wildlife managers do this by “dusting” — spreading an insecticide powder around burrow entrances, where the prairie dogs brush up against it coming and going and ultimately dust their coats, which kills most of the fleas they may be carrying. While the pesticide kills fleas, it’s not harmful to the prairie dogs or to other animals. The beneficial effects of one treatment last a long time; in some cases, a single treatment can keep plague outbreaks at bay for up to several years. Without the dusting, all prairie dogs in the colony would likely become infected, leading to a sudden and catastrophic population collapse where virtually no prairie dogs in the entire colony survive. When this happens, it can take a decade or more for prairie dogs in that region to recover their former numbers, if ever. To keep plague in check, dusting has become a critical tool in the arsenal to save ferrets and prairie dogs, and the role of the MCC applicators is equally critical.

All of this is taking place in a critical landscape: Thunder Basin is the single most important prairie dog habitat anywhere in the Great Plains today. Elsewhere, plague has ravaged concentrations of prairie dogs, reducing the population of prairie dogs at Conata Basin, South Dakota, for example — formerly home to 30,000 acres of prairie dog colonies and the largest black-footed ferret population anywhere — by nearly 70%. Defenders estimates the current prairie dog populations at all existing black-footed ferret reintroduction sites are less than half what they were in 2008. Such a low number of prairie dogs is profoundly impacting the recovery of endangered ferrets, despite recent successes in places like Colorado and northern Montana to reestablish them. At 14,000 prairie-dog-occupied acres and growing, Thunder Basin represents the largest concentration of black-tailed prairie dogs existing anywhere. But it is also the only place with such a large population of prairie dogs where ferrets have not yet been reintroduced. That’s why Defenders and others are challenging a plan being pushed by the Governor of Wyoming that would force the U.S. Forest Service to poison prairie dogs at Thunder Basin.

At the Governor’s request, the agency would use taxpayer money to poison prairie dogs — a practice that some ranchers support because prairie dogs eat grass, and so do cattle. It was the poisoning of prairie dogs throughout the west over many decades that ultimately led to their decline, and also to the black-footed ferret becoming endangered. More than 56,000 Defenders supporters submitted comments opposing the plan in the first round of public comment. While we have not stopped this ill-conceived proposal yet, the Forest Service is now working to determine what impact the plan could have on prairie dog recovery, and we expect to see their findings later this year.

Back at Thunder Basin, during a break in the dusting work, one of the biologists takes me to visit another nearby prairie dog colony. This colony is special. In 2009, Defenders and our NGO partners began assisting the Forest Service by taking prairie dogs from areas where they were destined to be poisoned, and moving them to the interior of the grassland where they were fully protected and less likely to spread onto private lands. This colony was essentially created from scratch on the site where an old, abandoned colony existed. From that small start of a couple hundred prairie dogs, the colony has now grown to occupy more than 500 acres. In their role as keystone engineers, the prairie dogs have modified the grassland structure, which now resembles a lawn more than a forest of grass. As it turns out, this type of grassland structure is also preferred habitat for the rare mountain plover, a shorebird that has evolved to live in arid grasslands. In a matter of a year, a dozen or more of these birds have seemingly arrived out of nowhere to occupy this “new” neighborhood and have already fledged chicks here.

The work at Thunder Basin is already producing results for prairie dogs and other species that depend on them for survival. We’re showing that there are non-lethal ways to manage the prairie dogs here at Thunder Basin that can also expand habitat opportunities. Poisoning prairie dogs with taxpayer dollars when there are alternatives that promote conservation is an outdated and lackadaisical form of wildlife management that is out of place in today’s world. Even in a remote place like the Thunder Basin, we need creative solutions to coexist with wildlife in a world where habitat is increasingly under pressure from development and human encroachment.

Steve Forrest is the Senior Rockies & Plains Representative for Defenders of Wildlife