Wolverine status still under watch
Coming back from the brink of extinction in the Lower 48, the wolverine has made a remarkable recovery in the past 50 years.
However, research suggests that the wolverine may become endangered in the future as a result of habitat loss, specifically spring snowpack.
Deep, persistent spring snow is crucial for successful wolverine reproduction because wolverines dig elaborate dens in the snow for their offspring. Climate modeling predicts that the wolverine’s habitat will be reduced by 31 percent by 2045 and 63 percent by 2085.
The US Fish and Wildlife Service expects the wolverine’s habitat to become more fragmented, which would support fewer wolverines and reduce connectivity between populations.
“The primary threat is habitat loss due to climate warming,” said Ben Conard, USFWS North Idaho Field Office Supervisor. “The limiting factor is persistent snow that it uses to den in the spring, which is becoming more sparse.”
The predicted habitat loss of spring snowpack is the reason why the USFWS has proposed to protect the North American wolverine as a threatened species in the Lower 48. The wolverine has been considered for listing since 1994 and a recent ruling dictates that the USFWS must decide by the end of 2013.
On Feb. 1, the USFWS proposed to list the wolverine as a threatened species in the Lower 48 under the Endangered Species Act. The public comment period for the proposal is open until May 6, 2013.
The biggest impact of listing the wolverine as threatened would be cessation of recreation fur trapping of wolverines in Montana. In the Lower 48, Montana is the only state in which wolverine harvest is legal.
“Wolverines can barely reproduce themselves in their life time,” said Conard. “There are no surplus animals. One that is knocked out of the population cannot add to the population.”
In the proposed rule, the incidental take of wolverines during the course of legal trapping of other species would be prohibited. Incidental take is not a big problem according to Conard.
In the 2008-2009 trapping season in Montana, two wolverines were incidentally killed in traps set for other species. In Idaho, three wolverines (one each in 2004, 2005 and 2010) were incidentally trapped in conjunction with trapping wolves involved in livestock depredations.
“If you want to comment on the exemption of incidental taking, include what would you do and ways to minimize picking up wolverine,” said Brian Holt, USFWS senior biologist at an informational meeting on April 1.
The comment period for this proposed rule is open through May 6, 2013. Comments are welcome on all aspects of the proposed rule including the proposed special 4(d) rule.
The special 4(d) rule outlines what is prohibited and what is compatible with the listing. For the wolverine listing, intentional take of the wolverine due to trapping, hunting, shooting, collection, capturing and trade would be prohibited.
Human activities would not be prohibited in wolverine habitat, such as snowmobiling, backcountry skiing and land management activities including timber harvest and infrastructure development.
“The best science says that human activities are not a threat,” said Conard.
The wolverine has rebounded from extinction in the last 50 years concurrently with human activities. The wolverine population is actually increasing said Conard.
“We are trying to be proactive,” said Conard. “Listing would bring interstate cooperation and build resiliency into the population. It opens up the tool box.”
No critical habitat has been proposed because the USFWS has found designation of critical habitat to be “not determinable” at this time. The USFWS has one year to develop a critical habitat proposal after the official decision said Conard.
“It concerns me that you will have to look at critical habitat in a year,” said Boundary County Commissioner Dan Dinning. “There could be additional restrictions in the future.”
For more information on the proposed listing and for how to comment, visit http://www.fws.gov/mountain-prairie/species/mammals/wolverine/.