BOULDER, Colo. –
But despite Boulder County’s vigilant efforts, prairie dogs on county open space keep popping up where they’re not wanted.
“Their annual population growth is far greater than whatever we’re going to be doing out there in any given year,” said Ron Stewart, director of the county’s Parks and Open Space Department.
Tuesday, the county’s Board of Commissioners will discuss whether to approve the latest update to its 10-year-old plan for how to manage prairie dogs on open space land.
The update does not outline significant changes to management strategies, which generally protect prairie dogs from extermination, but it does show how the furry rodents have maintained a tenacious paw-hold on “no-prairie-dog areas,” land that is farmed or where the ecology is otherwise unsuitable for prairie dogs.
The number of “no-prairie-dog” acreage that is, in fact, filled with prairie dogs has slightly more than doubled from a decade ago. And while a lack of predators and the acquisition of more farmland by the county has compounded the problem, the underlying cause seems to be that the colonies are growing and expanding faster than the county can trap them.
In 1998 the always-contentious prairie dog debate became even more inflamed after police arrested several people protesting a developer’s extermination of the animals near Lafayette’s city hall. In response, the county, which also had a policy of exterminating the animals when found on agricultural land, created a new strategy for dealing with prairie dogs in 1999.
The plan divided potential prairie dog habitat owned by the county into three categories: prairie dog habitat conservation areas, where the animals could be left to live without human intervention; multiple-objective areas, where prairie dogs could live but where they might not be the highest management priority; and no-prairie-dog areas.
At first, open space staffers worked to trap animals and move them to the habitat conservation areas. But in just a few years, those lands became full.
Since 2002, trapped prairie dogs — with nowhere to go — have been sent alive to feed the endangered black-footed ferrets bred at the U.S. Fish and Wildlife Service’s facility in Carr, Colo., or sent frozen to raptor rehabilitation centers on the front range.
But now, as more Colorado cities and counties have begun to trap prairie dogs instead of exterminate them, there aren’t enough raptors and ferrets to eat the available animals.
“We’re all making contributions to the same places,” said Mark Brennan, wildlife specialist for the county. “It’s become a little bit too popular, especially with the ferret program.”
Despite a four-fold increase in the total amount of open space land occupied by prairie dogs, the county isn’t looking at altering its management strategy. But if the animals win protection under the Endangered Species Act, a possibility under consideration by the federal government, the county could be forced to make changes.
Black-tailed prairie dogs live on as little as 2 percent of their historic lands, according to the U.S. Fish and Wildlife Service, which used to stretch across 11 states from Canada to Mexico. But the surviving colonies are not equally spread out, and prairie-dog- friendly Boulder County has some of the highest burrow densities of any place on the Front Range, with 270 burrows per acre in some places, according to researchers at the University of Colorado.
Historic densities were likely closer to 35 burrows per acre.
This kind of prairie dog clumping raises concerns about whether federal protection would force counties like Boulder — with lots of animals — to enforce the same protections as counties like Phillips and Sedgwick in northeastern Colorado where prairie dogs have become rare.
“The entire preservation of the species,” Brennan said, “cannot be bottled up in eastern Boulder County.”