Wolverine protection a matter of priorities

Yakima, Wash. -  Wolverines were trapped, poisoned and hunted out of existence in the lower 48 states decades ago, and now that they’ve begun to regain the thinnest of footholds in this country, they face an even greater challenge: climate change.

Federal wildlife officials believe the species deserves protection under the Endangered Species Act, but with this caveat: Wolverines are going to have to get in line.

The U.S. Fish and Wildlife Service on Monday assigned wolverines a “warranted but precluded” status under the ESA, which means the species warrants protection but the service is “precluded by the need to address other higher priority species.”

Those “higher priority” species include some of the 251 other species that were already official “candidates” for ESA protection. They range from the Arizona treefrog, Yosemite toad and Tucson shovel-nosed snake to the Lanai tree snail, the Mardon Skipper butterfly and rare plants like the Florida prairie-clover.

Wolverines were given a “listing priority number” of six out of a possible 12, putting them right in the middle in terms of how imminent the Service considered their particular peril.

There are fewer than 300 wolverines now living in the Lower 48, and only six verified as residents in Washington state. But until researchers captured and radio-collared a female wolverine near Harts Pass in the North Cascades in February 2006, it had been eight decades since even one had been verified in Washington.

Some observers wonder why that isn’t an elusive enough population to warrant immediate protection.

“If you’ve only got 300 in the country, hey, we’ve got other species where we know we have thousands, but they’re still listed as threatened or endangered,” said John Rohrer, who helped trap and collar that wolverine in 2006 and has radio-collared five others since. “With numbers that low, you’d think they’d be a higher priority.

“On the other hand, I don’t see it as there’s going to be a whole bunch of difference if they were listed. They’re hard to find, and at least right here where we’re working, they’re primarily living in the (designated) Wilderness or the National Park. So it doesn’t seem like there’s a whole lot going on that’s affecting them, human-wise. They’re not being trapped in Washington, and that’s probably the biggest thing.”

Wolverines are already listed for protection by all four states that currently have small resident populations — Washington, Idaho, Wyoming and Montana, although Montana still offers trappers a handful of wolverine permits each year.

Keith Aubry, Washington’s leading expert on wolverines and a research biologist at the Forest Service’s Pacific Northwest

Research Station in Olympia, said the announcement was a good start.

“Wolverines have a generally low reproductive rate and there’s not a lot of room for additional mortality without having an adverse effect on the population,” Aubry said. “I think simply raising awareness that there are reasons for conservation concern would be a good thing.”

But climate change poses an even greater challenge to wolverines’ survival than mankind does.

“They need high-altitude, cold country to survive,” said Doug Zimmer of the Fish and Wildlife Service. “They need cold weather, they need 8 to 10 feet of snow to den in, because they den in snow or under sheltering logs and deadfall that are under snow.

“They do that because the female raises the kids pretty much on her own and she needs to leave them in a secure place to go out hunting and scavenging. So she needs that deep snow that will still be there up into April, when the kits are not so vulnerable.

“As those areas of deep snow decrease, that’s going to be more of a threat to wolverines.”

According to one recent study, said Dave Werntz, science and conservation director of Bellingham-based Conservation Northwest, “If things stay the same, wolverines will lose up to 60 percent of their habitat by the end of the century. That would be a challenge for any species.”

Conservation Northwest (then called Northwest Ecosystem Alliance) was one of several groups that petitioned the Fish and Wildlife Service in 2000 — after a similar petition failed in 1995 — to institute federal protection of wolverines. The Service ruled in 2008 that protections were not warranted but, following a suit by conservation groups, reconsidered its position.

Wolverines’ historical range in the western United States was from the Canadian border south to Colorado in the Rockies and as far south as California’s Mount Whitney in the Sierras. “Except that the California population,” Aubry noted, “based on the genetic work that we’ve done was an isolated island population.”

In the last decade, scientists have been able to verify the extraordinary range of some wolverines. One animal that was radio-collared in the Tetons of northwest Wyoming made it to the Rocky Mountain National Park in Colorado, while another one that originated in Idaho showed up near Lake Tahoe on the California-Nevada border.