HELENA — Six environmental groups petitioned the federal government Monday to enact endangered species protections for the Northern Rockies fisher, saying increased trapping in Montana and Idaho is killing more of the small, weasel-like predators.
The fisher, which lives in old-growth forests in western Montana and northern Idaho, preys on porcupines, snowshoe hares and other small animals and birds. There is no comprehensive population estimate for the predators, though environmental groups believe up to 500 may be living in the Northern Rockies.
“But nobody actually knows,” said Tierra Curry, a conservation biologist for the Center for Biological Diversity. “We know they have come back in a couple of places, but there is no overall data available.”
The Center for Biological Diversity and five other environmental groups filed their petition with the U.S. Fish and Wildlife Service seeking to designate the Northern Rockies fisher as an endangered or threatened species. A similar petition was rejected in 2011 when federal wildlife officials determined trapping, logging and residential development did not appear to be hurting fisher populations.
Since the original petition was filed in 2009, trapping has increased in Idaho and Montana, the environmental groups said. Since 2008, the number of fishers caught in traps set for other animals has more than doubled compared with those trapped between 2002 and 2007, they said.
Research that was lacking in 2009 has produced more information about the Northern Rockies fishers’ habitat in old-growth forests, and should bolster the new petition, Curry said.
The fisher is listed as a sensitive species U.S. Forest Service’s Northern Region, which includes Idaho and Montana. Montana considers the fisher potentially at risk because of limited or declining numbers, range or habitat. But the state says the predator may be abundant in some areas and it allows limited trapping of the animals.
Idaho has no open season for fishers and considers the predator critically imperiled. Even so, 76 fishers were caught in traps meant for other animals in Idaho between 2010 and 2012, 22 of which were killed, according to the Center for Biological Diversity.
The Fish and Wildlife Service has 90 days to determine whether information in the petition is substantial enough to warrant further study. The agency may issue a negative finding or decide to gather more information.