"We feel the population is at a historic high level from the time of European settlement, and we can wait and see what happens with climate change in the next 20 to 30 years." Bates said.
The proposed listing by the U.S. Fish and Wildlife Service (FWS) is based in part on modeling that shows wolverines rely on snow-covered terrain for 5 ½ months during their denning season, between January and May 15.
"Wolverines are in the coldest and snowiest places in the lower 48 [states] during that time, and they also seem to use that area year-round," said Shawn Sartorius, a FWS biologist focused on listing, delisting and recovery of endangered species.
As has been the case for other species, namely polar bears and some corals, climate change was a factor, he said.
"But for climate change we would not have been proposing [wolverines] for listing," he said. "A lot of people don't understand listings always include projecting threats."
Restoring the wanderers • The North American wolverine population is estimated to be around 300 animals in the lower 48 states which is more than 100 years ago, Sartorius said.
Wolverines, famous for their wandering ways and ability to survive tough conditions, were eradicated from the lower 48 states by about 1920. Since then, animals from Canada have moved into Montana, Idaho, Wyoming and Washington state. Colorado and California each now have one male wolverine resident.
"We have never had documentation of a breeding pair in Utah, but we definitely see transient males just passing through," Bates said. "We have wolverine sightings reported almost every year in the same locations, and it is consistent enough to have me believe that, even if they are not verified, that there is probably something there."
Recent confirmed sightings came in 2003 near Morgan and in the Bear River ranges near Logan in 2005.
FWS is proposing an area for a "nonessential, experimental" population of transplanted wolverines, which would include portions of Colorado, Wyoming and New Mexico. There would be no new restrictions on land use or activities in the designated area.
Utah is not part of the current plan. Wolverines that wander into the state, if the species are listed as threatened, would be protected like all animals on the Endangered Species list with special rules on trapping and managing the population.
If a wolverine reintroduced in Colorado is found in Utah, wildlife officials could capture it and send it back or allow it to remain under those protections.
'The ultimate goal' • Federal protection is not always the best thing that can happen for a species, Bates said. State biologists may be more familiar with what animals need to avoid declining populations.
Utah does have suitable wolverine habitat and reintroduction of the animals could be considered with or without a listing on the Endangered Species list, but it would have to be approved by the Utah Wildlife Board and the Utah Legislature, Bates said.
Sartorius, who attended the association's meeting in Salt Lake City on Nov. 7, said the FWS will take the states' letter into consideration. He noted that more than 100,000 comments have been received on the proposed listing.
A listing, he acknowledged, "can make things more difficult for political reasons and there is a resistance to the Endangered Species Act and a fear of regulations."
The FWS recognizes the potential for problems, he said. "We understand it is very important for us to work with state agencies to achieve the ultimate goal of protecting species."
Kylie Paul, Rockies and Plains representative for Defenders of Wildlife, said, "Any kind of a delay [in listing wolverines] is really a waste of time and taxpayer money."
The evidence is clear that wolverines rely on snow-covered terrain for up to half of the year and that it is critical for denning females, Paul said.
"We need to be moving forward and doing anything that would increase their chance of recovery," Paul said. "This is a cold-dependent species, and it can only be assumed that its population will decrease over time as temperatures continue to climb."
The U.S. Fish and Wildlife Service published its proposed rule to list the North American wolverine as threatened under the Endangered Species Act on Feb. 4. The first comment period ended May 6.
It later opened a second public comment period, which is slated to end Dec. 2. Find details about how to comment here.
The service says it intends to issue a final determination on the rule by Feb. 4, 2014.
North American wolverine
The U.S. Fish and Wildlife Service is considering a proposal to list the wolverine as threatened on the Endangered Species List. Some details about the elusive and wide-ranging mammal:
• The largest terrestrial member of the family Mustelidae, it weighs up to 40 pounds.
• It resembles a small bear with a bushy tail.
• States they are known to or believed to inhabit: California, Colorado, Montana, Nevada, Oregon, Utah, Washington and Wyoming.
• A transplant of the animals that would impact Colorado, Wyoming and New Mexico is being considered. That population would be considered experimental.
Source: U.S. Fish and Wildlife Service