Colorado wolverine reintroduction bill introduced in statehouse

Colorado could return another native carnivore to its mountains if state lawmakers pass a bill allowing for the reintroduction of wolverines.

The bipartisan bill — if passed — would allow Colorado Parks and Wildlife to accomplish a decades-old goal to restore the elusive and wide-roaming weasel to the state.

“Colorado is the right state to take on this work,” Colorado Parks and Wildlife Director Jeff Davis said in a news release. “The North American wolverine requires a high-elevation habitat with persistent, deep snowpack, and Colorado has some of the best remaining unoccupied wolverine habitat in the lower 48 states.”

The 40-pound weasels wander broad swaths of high alpine territory extending up to 600 square miles and can cover up to 15 miles a day. Wolverines primarily feed on carcasses but will also kill rabbits, rodents and other small animals. Occasionally, they kill livestock. Wolverines are not related to wolves, despite similar sounding names.

Reintroduction would likely take several years if the bill passes. State wildlife officials must complete a federal process to create management guidelines for the threatened species.

“If the bill passes, a number of items will need to be tended to before wolverines could be released and it is difficult to project how long each item might take,” Colorado Parks and Wildlife spokesman Travis Duncan said. “For instance, a 10(j) ruling will have to be published by the U.S. Fish and Wildlife Service before a reintroduction could proceed, and that process alone could take a few years.”

Wolverines once roamed from the Sierra Nevada in California to the Rocky Mountains but were nearly exterminated from the lower 48 states by the early 1900s as large game herds decreased and people poisoned carcasses to kill wolves, bears, coyotes and mountain lions.

Large populations remained in Canada and Alaska and the wide-roaming species have since re-established in Washington, Montana, Idaho, Wyoming and Oregon. Biologists estimate there are  approximately 300 wolverines in the lower 48 and thousands in Canada and Alaska.

Colorado Parks and Wildlife biologists estimate that up to 180 wolverines could live in the state — a significant increase to the population in the contiguous United States.

Wolverines require habitat with deep and long-lasting snowpack — territory that will become harder to find as climate change shortens winters, according to the U.S. Fish and Wildlife Service. Colorado is expected to retain its snowpack better than lower-elevation mountains across the West and could provide a key refuge for the species, state biologists have said. 

Federal officials in November deemed wolverines a threatened species under the Endangered Species Act in the lower 48 states, citing habitat loss and climate change as threats to the species.

“The tenacious wolverine can thrive by scavenging in a harsh world of snow and ice but is defenseless against the looming threat of human-caused climate change and loss of snowpack,” Michael Saul, Rockies and Plains program director for Defenders of Wildlife, said in a news release. “That’s why it’s so important for the survival of the species that Colorado moves forward with returning these animals to the high mountains of the state, where we can help give them a fighting chance at survival.”

Wolverines have not been seen in Colorado since 1919, except for one lone critter who wandered through the state between 2009 and 2012. That wolverine traveled 585 miles over a few months from the northwest corner of Wyoming to the mountains outside Breckenridge. It later wandered to North Dakota, where it was shot and killed.