TELEGRAPH CREEK — Randy Matchett calls it his chart from hell.
Rising and falling like heartbeats recorded on an electrocardiogram, the lines show the surge and decline in black-footed ferret kit reproduction in the past 17 years in the Charles M. Russell National Wildlife Refuge in northeastern Montana.
“We have tried about everything we can for black-footed ferrets,” said Matchett, a wildlife biologist for the U.S. Fish and Wildlife Service on the CMR.
Despite all his work, the endangered animals that have been brought back from the brink of extinction can’t seem to find a firm toehold here.
Back from the edge
Related to skunks, badgers and wolverines, black-footed ferrets once ranged across the Great Plains from Mexico north into Canada. Thirty years ago, they were believed to be extinct until a population of 129 was discovered in a prairie dog town near Meeteetse, Wyo. All but 18 of that small group had died only four years after their discovery. To preserve them from extinction, 14 of the survivors were trapped and seven were bred in captivity by the U.S. Fish and Wildlife Service. From the offspring of those few ferrets, the animals have been reintroduced to 19 prairie landscapes in Wyoming, South Dakota, Colorado, Utah, Arizona, Kansas, Canada, Mexico and in Montana.
In Montana, ferrets were reintroduced at the Fort Belknap and Cheyenne reservations, on Bureau of Land Management property south of Fort Peck Reservoir and in the CMR. To date, only the CMR has a documented surviving population of 22 ferrets.
The CMR got its first 35 of the sleek-bodied, masked-face members of the mustelid family in 1994. They were released on the U.L. Bend National Wildlife Refuge — a refuge inside the larger CMR. Since then, the refuge staff has documented birth in the wild of 276 kits.
Tied to dog towns
Black-footed ferrets rely on prairie dogs for their food and shelter — living in the same burrows as prairie dogs. Prairie dogs are small, burrowing rodents that denude the landscape around their homes, called dog towns. Because they compete with cattle for land, they have long been poisoned and shot.
According to Matchett, between 1930 and 1933 in Phillips County alone an estimated 300,000 acres of prairie dog towns were poisoned.
There are only about 3,500 to 4,000 acres of prairie dog towns in the CMR, where prairie dogs are protected, down from a high of 8,000 to 10,000 acres. Yet even on this protected landscape, prairie dog towns haven’t thrived, limited by the rough topography and terrain, Matchett said.
“We’re pretty marginal prairie dog habitat,” he said.
Adding prairie dog habitat outside the refuge is tough, he said, because of landowner indifference or outright disdain for the animals.
Decimated by disease
Prairie dog populations are also limited by outbreaks of sylvatic plague, which can eliminate entire colonies — including the one that supported the few remaining ferret survivors in Meeteetse.
“I watched a 1,300-acre prairie dog town die in three weeks from an outbreak,” Matchett said.
To combat outbreaks, CMR biologists have gone as far as dusting prairie dog towns with flea killer to eliminate the disease-transmitting organisms and vaccinating ferrets against the plague. Both worked to decrease plague outbreaks and deaths, more than doubling survival, when compared with a control group that wasn’t treated.
The next step is testing of an oral vaccine for prairie dogs, planned for next year.
Such intensive management and human intervention to keep the black-footed ferrets alive is not something Matchett likes. When they were initially reintroduced to the CMR, he said the plan was to establish a viable population of ferrets that would be self-sustaining. The plague changed all of that, and the CMR revised its vision to focus on research to better understand the plague. More recently, black-footed ferrets have become a charismatic species, attracting attention and tours from wildlife groups as an ambassador for understanding prairie habitat.
Matchett is concerned that kit production by next year may drop so low as to require more reintroductions to keep the species viable on the CMR.
“I’m not very satisfied to call them recovered when you have to do this annual intervention,” Matchett said. “It’s a pretty frustrating story.”
Contact Brett French, Gazette Outdoors editor, at email@example.com or at 657-1387.