Sylvatic plague hits prairie dogs, ferrets in BadlandsOn the Conata Basin, a sprawling piece of prairie and badlands touching some of the national park and a lot more of the Buffalo Gap National Grasslands, the losses have been staggering to the national ferret recovery effort.
By: KEVIN WOSTER, The Rapid City Journal
WALL — Racing their ATVs through a prairie-dog town on federal grasslands north of Badlands National Park, members of Matt Kelly’s crew lurch to brief stops at each burrow and fire blasts of white powder into the holes.
Precision is important. The insecticide being fired from the end of well-aimed wands by Kelly and his crew from Gopher Chokers pest control of Scenic is helping to save an endangered species.
Crew members must hit every hole they can to save every prairie dog possible from sylvatic plague, an explosive, flea-borne disease that tears through prairie dog colonies with storm-like devastation.
And when the dogs die, the ferrets soon follow.
On nearby Conata Basin, a sprawling piece of prairie and badlands touching some of the national park and a lot more of the Buffalo Gap National Grasslands, the losses have been staggering to the national ferret recovery effort.
What was once the largest ferret population on the continent has shriveled from an estimate of 335 in the fall of 2007 to 72 last fall.
All because of the plague. And all because of the fleas that carry it.
Watching from his U.S. Forest Service pickup as Kelly and his crew make frenetic stops, starts and turns, wildlife biologist Randy Griebel compliments their efficiency and predicts a dismal future for ferrets without the insecticide.
“Oh, they’d all be gone around here,” he said. “If we weren’t dusting, we’d be about plagued out. There might be a couple hundred acres total of prairie dogs scattered throughout the area. Not enough to sustain ferrets.”
It takes plenty of space and plenty of prairie dogs to sustain ferrets, which rely on the burrowing rodents for about 90 percent of their food supply. As prairie-dog populations declined to a small fraction of their native North American territory in the face of habitat loss and poisoning and disease, ferret populations faltered.
The tiny member of the weasel family, a mostly solitary, nocturnal hunter, was feared extinct by the late 1970s. But a wild population was discovered a few years later near Meeteetse, Wyo., and a captive-breeding and reintroduction program began.
Eventually the Conata Basin had bragging rights for the most wild black-footed ferrets anywhere. It also was the home to controversy over the numbers of grass-grubbing prairie dogs, which many ranchers considered a plague of another kind.
But that was before the real plague hit.
“We’re not the leader anymore,” Griebel said of wild ferret populations. “Shirley Basin out in Wyoming’s got more. I think they’ve got more on the Cheyenne River Reservation.”
That other areas have important populations of ferrets is the good news, although biologists all worry about the plague. Pete Gober, project leader of the Black-footed Ferret Recovery Program based in Wellington, Colo., oversees ferret work and keeps tabs on the population, in captivity and the wild.
Gober said the Shirley Basin area of southeast Wyoming is probably the leader these days in ferret numbers, with an adult spring population of about 100. Gober uses the spring adult population because “that’s when they really matter, when you’re through winter and you have adults ready to give birth.”
Gober estimated there are probably about 50 adults this spring in the Conata Basin, another 50 or so on the Cheyenne River Reservation and 50 down in the Aubrey Valley in Arizona, along with 25 adults this spring in Wind Cave National Park in the southern Black Hills and 25 in Kansas.
There also is a “smattering at locations elsewhere,” Gober said. When all ferret populations in the wild are added up, the total is 300 to 400 springtime adults, he said. There also are about 300 adult ferrets in captivity, spread out between the U.S. Fish & Wildlife Service center in Colorado and five zoos.
Getting exact counts on ferrets in the wild is difficult, Gober said.
“You have to remember, these are things that are difficult to count. They’re out in remote places in the dark,” he said. “So it may be difficult to have precise numbers.”
On the Cheyenne River Reservation, Prairie Management Program director Mike Claymore figures he had about 100 ferrets going into winter last year, thanks in part to recent reintroductions from elsewhere.
Claymore said the plague hasn’t hit there yet, but the tribal program can’t afford the dusting effort now in progress near Wall.
“With the poverty level here, we really couldn’t justify spending resources on killing fleas to protect prairie dogs for ferrets,” he said. “As a contingency against plague, we’ve chosen to have several ferret sites miles apart. Right now we’ve still got ferrets and prairie dog numbers. Hopefully the ferrets can hold their own for a while.”
That is what Griebel is hoping for as he oversees the dusting programs that fight the plague in key ferret-recovery areas near and in the Badlands. It is an annual expense and chore that will be necessary until the plague loses its grip on the Conata Basin and grasslands nearby, Griebel said.
The program he manages out of the Wall office will dust 11,000 acres to 12,000 acres this year on the national grasslands allotments. Another 2,000 acres or so will be dusted in Badlands National Park.
Griebel is there regularly to oversee the work, which includes following Kelly and his crew through flagged-off treatment lanes to make sure they get almost every burrow.
“Their contract says they have to hit at least 95 percent of the burrows in each lane,” Griebel says. “They do better than that, usually 98 or 99 percent. Sometimes they hit them all.”
It works in maintaining reduced prairie dog acreages that allow likewise-reduced ferret populations to survive. Griebel doesn’t have to drive from where the dusting crew was working to see what can happen without the insecticide treatment.
“You go down along lower Sage Creek and there’s nothing left down there,” he said. “It used to be you’d drive along Highway 44 and it was pretty much prairie dogs as far as you could see. Now it’s nothing.”