New studies give insight into elusive wolverine
On Valentine’s Day, scientists gave Melanie a necklace with a satellite transmitter. The pregnant wolverine snarled, growled and hissed before ambling off into the icy wilds of Washington’s northern Cascade Range.
The collar sends back signals, giving biologists a rare glimpse into the world of one of the fiercest and least known creatures of the West. The study is one of several now under way and will likely be used in coming months to determine if wolverines should be protected under the Endangered Species Act.
Conservation groups have been pushing for federal protections since 2000, but the Fish and Wildlife Service has previously rejected the petitions, saying not enough information was available.
On Tuesday, the U.S. Fish and Wildlife Service launched a court-ordered review of all scientific information on wolverines, including several new studies to be published later this summer. The agency has until February to finish the review.
Wolverines could be especially vulnerable to backcountry winter recreation and the West’s decreasing snowpack, according to preliminary results from studies to be published this summer in the Journal of Wildlife Management.
Jeff Copeland, a U.S. Forest Service wolverine expert leading much of the research, said the animals appear to require a thick blanket of spring snow and lots of quiet to reproduce.
“Where these animals den is the same area where we like to recreate. It’s probably the single most important (wolverine) management issue the Forest Service faces,” said Copeland, whose granddaughter is the namesake for Melanie.
Lighter, faster snowmobiles and helicopter skiing now allow people to venture into previously inaccessible alpine terrain. Conservationists, including Gary Macfarlane, with Friends of the Clearwater, worry that wolverine, lynx and other alpine species will perish unless quick action is taken to keep the winter backcountry quiet.
“The problems are a function of changing technology and federal land management agencies being derelict in their duties,” said Macfarlane, the ecosystem defense director for the Moscow, Idaho-based group. Friends of the Clearwater was one of several environmental groups that sued the federal government in 2005 to protect wolverines.
The animals were nearly poisoned and trapped out of the West by the 1930s, Copeland said. They’ve never returned to Colorado or California, but this largest member of the weasel family has since made a slow recovery in parts of Montana, Idaho, Wyoming and Washington.
If the alpine sanctuaries are lost – whether by climate change or increasing incursions from people – the luck of the wolverine could soon run out, said Joe Scott, with Conservation Northwest, a Bellingham-based group that was a plaintiff in the federal lawsuit.
“These are the only populations left,” he said. “If you only have these small populations left, you better do due diligence about how you manage recreation in those areas.”
Nobody knows for sure how many wolverines remain in the lower 48 states. Copeland put the figure at “a few hundred,” with the highest population density in Glacier National Park, where roughly 45 live – compared with about five times as many grizzly bears. Central Idaho is also believed to have one of the healthier populations. Fewer than 20 are known to roam the coldest, snowiest reaches of north-central Washington.
Copeland and his fellow researchers have been conducting an exhaustive review of museum and state records to get an idea of how common wolverines were in the West. They’ve examined old pelts, photographs and trapping log books. To verify the records, they went so far as calling descendants of the trappers who pose with dead wolverines in old photographs, Copeland said.
The researchers have also been burrowing deep into wolverine dens in Montana to implant transmitters in kits and put collars on their mothers. The Forest Service and the Washington Department of Fish and Wildlife have also been conducting a study in the north Cascades to catch and collar wolverines.
Each bit of new information represents a big step forward in our understanding of wolverines, said Copeland, who works out of the Forest Service’s Rocky Mountain Research Station in Missoula. Until now, there have been only 12 studies attempted on North American wolverines, and only four have produced publishable results.
“We’re starting to get some basic information, but we’re still a long ways off,” Copeland said. “This is an animal we’ve not paid very much attention to.”
The little that is known has left researchers in awe. Wolverines have frost-proof fur, snowshoe-like paws and jaws strong enough to crush bones and tear apart frozen flesh. Their claws can scale steep, icy cliffs or dig through 15 feet of snow to chow on colonies of hibernating marmots. Wolverines can also be ferocious – grizzly bears in Glacier National Park have been known to avoid them.
Chewbacca, a wolverine trapped and collared twice this winter in the north Cascades, gained 2 pounds between January and March, said John Rohrer, a Forest Service biologist in Washington’s Methow Valley Ranger District. “They’re built for winter. They can get around on snow better than any other animal. They’re fascinating, really.”