The federal government will begin poisoning prairie dogs in southwestern South Dakota next week after reaching a deal with conservationists designed to protect the endangered black-footed ferret.
The U.S. Department of Agriculture agreed to distribute poison on only 5,000 acres instead of about 8,000 acres in the Buffalo Gap National Grasslands, including the Conata Basin, where more than half of the nation's 400 wild ferrets live.
Following complaints from neighboring ranchers that prairie dogs are spreading onto their property, federal officials plan to lay out poisoned oats on Monday.
Eight conservation groups sued, fearing some ferrets, which depend on prairie dogs for 90 percent of their diet, would also die. Both sides began negotiating a settlement last week at the urging of a judge.
The land excluded under the deal includes prairie dog towns where ferrets have been spotted. It reduces from one mile to a half-mile the buffer zone where the poisoning will take place in some areas.
In the future, the federal government also agreed to consider non-lethal methods of controlling prairie dogs and to study the impact of poisoning before moving ahead with another round.
Conservation groups were still upset that prairie dogs will be killed, but they said the settlement points the way toward a more permanent solution to the tension between ranching and wildlife.
"We hope to replicate those (solutions) in the future once we can show here how they work," said Jonathan Proctor of the Predator Conservation Alliance, one of the plaintiffs.
The conservation groups had sought to stop next week's poisoning until the impact on ferrets could be sorted out. But, because prairie dogs on the neighboring private land had already been poisoned, the government said it need to act quickly to prevent the animals from spreading onto the ranches before snow started to fall.
Critics worried that ferrets could die if they eat the bait or if they eat prairie dogs who have been poisoned.
Under the deal, the U.S. Fish and Wildlife Service will decide whether to move any ferrets discovered in areas slated for poisoning. If the agency decides to keep them there, no poison can be left in the area.