From Keystone Species to Ecosystem Transformer: The Changing Role of Prairie Dogs on the Front Range
Prairie dogs have long been a natural agent of change for ecosystems in the American West. But paired with recent climate change and human development, they are now turning certain Boulder grasslands into small-scale dust bowls.
During a recent visit to Teller Farm Open Space near Boulder, Colo., Tim Seastedt, a University of Colorado prairie ecologist, described this desertification process to a group of graduate students. A recurring plague is the only thing keeping the prairie dog population in check, he said, but the rodents may no longer be so susceptible.
“It’s impressive how they seem to persist,” Seastedt said.
The prairie dog has historically been a keystone species in the prairie grassland ecosystem, helping to create suitable habitat for a variety of other species, including burrowing owls and black-tailed ferrets. But the prairie dog’s role, too, is changing.
Seastedt now describes prairie dogs as “ecosystem transformers.”
Under normal conditions, the rodents relocate their colonies frequently so they can graze the short grass prairie and move on before the grass is gone. But today’s increased temperatures, longer growing seasons, and wetter winters mean the grass is being displaced by leafy plants and shrubs—many of them non-native.
According to Seastedt, "shrublands don't have the ecological service" of prairie grasslands. Not only are they less palatable for grazers, but they also cause increased wind erosion, which is becoming more common along the Front Range, including at Teller Farm.
Even if the grass is greener on the other side of the fence or road, habitat fragmentation no longer allows prairie dogs to cross these barriers, so their colonies are denser and put more strain on the environment.
The result is increased erosion and a loss of soil fertility, Seastedt said. The first reports of winter dust storms caused by prairie dog induced erosion came from Fort Collins in 2006 and have since been reported in Boulder with increasing frequency.
The congested prairie dog colonies are also vulnerable to sylvatic plague, a non-native disease for which the animals have historically had little or no resistance. But the increasing frequency of survivors suggests prairie dogs are now developing immunity to the disease.
Seastedt said the plague recurs approximately once every decade. Since the mid 90s, the plague has served as a convenient, if temporary, solution to the prairie dog overpopulation problem on the Front Range.
Prairie dogs are simultaneously protected by the Colorado Division of Wildlife and considered a pest by the state’s Department of Agriculture. And they are a source of contentious debate for land managers and local residents alike.
The City of Boulder Open Space & Mountain Parks manages prairie dog habitat within Boulder County. According to the 2009 Grassland Management Plan, that habitat consists of 5,200 acres in Boulder County and excludes tall grass prairies and the foothills. Another 5,000 are designated as Multiple Use Areas, which allow prairie dogs to colonize as long as they do not negatively impact the land’s other uses.
In terms of a long-term solution for the evolving grasslands and their furry inhabitants, Seastedt said he has “yet to find one that’s win-win for all involved.”