Plague threatens black-footed ferrets

A [South Dakota] colony that contains nearly half of the black-footed ferrets in the country and which biologists say is critical to the long-term health of the species has been struck by plague, which may have killed a third of the 300 animals. A much-publicized endangered species in the 1970s that had dwindled to 18 animals, the black-footed ferret had struggled to make a comeback and had been doing relatively well for decades. But plague, always a threat to the ferrets and their main prey, prairie dogs, has struck with a vengeance this year, partly because of the wet spring. The ferrets are an easy target for the bacteria. “They are exquisitely sensitive to the plague,” said Travis Livieri, a wildlife biologist here who is trying to save the colony. “They don’t just get sick, they die. No ifs, ands or buts.” Humans can catch plague, but it is easily treated with antibiotics. Mr. Livieri is working with the federal Fish and Wildlife Service’s black-footed ferret recovery team, the Forest Service and some volunteers to try to save the colony at Conata Basin by dusting prairie dog burrows with flea powder that kills the plague-carrying insects. Mr. Livieri is also working on a vaccination program, prowling the prairie all night to capture ferrets for injections.