There is a huge prairie dog town in the Conata Basin, a 20-mile long portion of the Buffalo Gap National Grassland that lies just south of Badlands National Park in southwestern South Dakota. Perhaps not surprisingly, the Conata Basin has proven to be the most successful of the nation’s 17 [url=http://www.defenders.org/programs_and_policy/wildlife_conservation/imper...
black-footed ferret[/url] reintroduction sites.
Last May, sylvatic plague began to spread like wildfire through the Conata Basin. By August the deadly disease had spread to some 9,700 acres of the prairie, killing nearly all of the prairie dogs as well as about 100 of the 290 ferrets living in the 25,000-acre ferret management area.
This plague variant affects only wild animals, so it is dubbed sylvatic.
Spread by fleas and highly infectious, plague poses a dreadful threat to the ferrets. The mortality rate for non-vaccinated ferrets is virtually 100 percent. Because the plague kills prairie dogs, it also depletes the principal food source for surviving ferrets.
Plague has not yet been detected in Badlands National Park, and this encourages scientists to believe that a vigorous program that combines insecticide spraying and vaccination might spare the remaining black-footed ferrets in the park as well as the Conata Basin.
The hot, dry weather of summer slowed the spread of the disease in the basin, giving biologists precious time to spray and vaccinate before cooler, wetter weather arrives. A crew of four has been traveling the prairie in ATVs, spraying flea-killing insecticide dust into prairie dog burrows. They’ve treated over 7,000 acres so far in the Conata Basin and hope to do another 4,000 by fall.
Another crew, which operates at night, traps ferrets and vaccinates them. More than 60 ferrets have been vaccinated so far (15 of them twice, which is the recommended dosage).
We’ll know soon enough whether the spray-and-vaccinate campaign produces the desired protection in the Conata Basin and Badlands National Park. Sylvatic plague also remains a credible threat to the ferrets at Wind Cave National Park and other reintroduction sites in the region.