Wildlife biologists operating in a remote area east of Salmon made an important discovery this spring when they found a "vortex of wolverine activity" in the roadless Beaverhead Mountains.
Based on results from a winter hair-snaring survey on the west side of the range that forms the scenic backdrop for this east central Idaho community, the biologists took to the air, looking for wolverine sign. Near the headwaters of Carmen Creek on the Idaho side of the Continental Divide, they spotted the species' distinctive tracks in the snow.
Back on the ground, they hiked into the area and made the rarest discovery of all: a maternal wolverine den complete with a nursing female and her two young kits. The largest member of the weasel family at about 30 pounds, wolverines are dark brown and have light stripes on their sides from head to tail.
The wolverine's Latin name Gulo gulo means glutton. Their preference for remote forests and high-mountain cirques makes the Smoky, Sawtooth, Boulder and White Cloud mountains some of the species' best habitat in the state.
Locating the den site for such an elusive and wide-ranging species of animal is rare, the Idaho Department of Fish and Game's Beth Waterbury said Thursday. Waterbury, Fish and Game's regional nongame biologist for the Salmon Region, led the hair-snaring project that resulted in the rare discovery.
"That was kind of a career high for me," she said.
Although the results of a DNA analysis of the wolverine hair is not yet complete, the amount of hair snagged in several locations in the Beaverheads suggests several wolverines may be occupying the area, Waterbury said.
The quest to find the wolverine den was funded by the nonprofit organization Wildlife Conservation Society, an international group dedicated to saving endangered wildlife and wildlands. Leading the project was Bob Inman, a wolverine expert in charge of the Wildlife Conservation Society's Greater Yellowstone Wolverine Program.
The wolverine den discovery comes at an especially crucial time in the management of the species. This week, 10 conservation groups announced that they will file a legal challenge against the U.S. Fish and Wildlife Service in an attempt to have wolverines living in the lower 48 states listed as a threatened or endangered species under the federal Endangered Species Act (ESA).
Back in March, the Fish and Wildlife Service announced that listing the wolverine in the same region wasn't warranted because a healthy population still persists in Canada.
The groups contend the agency's decision is justification for denying long overdue protections to the animal, which they say is imperiled and may number as few as 500 south of Canada. Conservationists first petitioned to have the wolverine listed nearly a decade ago.
Protecting the last remaining habitat for the wolverine in the lower 48 states is crucial in light of the effects global warming, the conservationists argue. The species is vulnerable to global warming because it depends on deep snow for everything from travel corridors to the snow dens where they raise their young, they say.
Wolverines once roamed across the northern tier of the U.S. and as far south as New Mexico and southern California. Conservationists say the wolverine is now reduced to small, fragmented populations in Idaho, Montana, Washington and Wyoming.
According to the groups, wolverines in the lower 48 states represent a distinct population that is only tenuously linked to the Canadian population and are in need of habitat and other protections.
"The Bush administration is essentially outsourcing responsibility for our wildlife to other countries," said David Gaillard, Rocky Mountain representative of Defenders of Wildlife, one of the groups involved in the lawsuit. "Wolverines are as American as the bald eagle, gray wolf and grizzly bear, all of which might have vanished from the lower 48 if the same reckless policy were applied to them.
"With global warming compounding the many threats facing snow-dependent wolverines, protections are needed more than ever to ensure that this magnificent animal continues to call the U.S. home."
The groups claim a March statement by the Fish and Wildlife Service that says, "the population (in the lower 48 states) will be at risk of extinction," is proof the agency was incorrect in its determination that ESA listing wasn't warranted.
Bozeman-based Earthjustice filed the 60-day notice of intent to sue on behalf of Defenders of Wildlife and the nine other conservation groups, which also includes Boise-based Idaho Conservation League.
Back up in the Beaverheads, Waterbury, Inman and the other biologists who discovered the den site fitted the wolverine kits—a male and a female—with radio transmitters. They had to dig down two meters to access the tunnel.
"They looked like miniature adults," she said.
Using radio telemetry equipment, Waterbury and the other biologists will now be able to track the young wolverines to determine how far they disperse from their birthplace to new home ranges.
Waterbury said knowing which mountain ranges act as linkage corridors for the far-ranging species will be especially crucial if wolverines are to be preserved in the northern Rocky Mountain region. Unlike contiguous wolverine habitat to the north in Canada and Alaska, Waterbury described the northern Rockies landscape as a sea of isolated and "discontiguous-type" habitat.
"It's like a gauntlet getting between what they're calling sky island habitat," she said.
Waterbury said the team was unable to place a radio collar on the adult female, especially not after she showed off a display of the ferocity for which wolverines are legendary.
"She busted out of the maternal den and hovered off in the distance," she said.
Tracking the young wolverines could be a challenge if the past is any guide. Several years ago, Fish and Game biologists working along north central Idaho's Lochsa River in April fitted an adult wolverine with a radio collar.
Within weeks, they had lost the animal's signal. But several months later in July, the male wolverine turned up 160 air miles to the south deep in the Salmon River Mountains. His amazing journey would have taken him through the rugged Selway Bitterroot and Frank Church-River of No Return wilderness areas, she said.
"When they want to move, they move."