Fisher Resurgence: Once extinct in Pennsylvania forests, a big active predator is on the rebound
January 8, 2017 12:00 AM
Fishers sited in southwestern Pennsylvania likely came from restored West Virginia populations, despite a similar Game Commission program in northcentral counties.
By Ben Moyer / Special to the Post-Gazette
The fisher, Pennsylvania’s second-largest member of the weasel family (the river otter is largest), is poorly named. “Mouser” or “squirreler” might be better.
Although fishers prey on diverse food sources, fish are not part of their diet. Small rodents, rabbits, squirrels and carrion make up much of the menu, and fishers are effective predators of porcupines where that prey is available. But biologists who have worked to re-establish the fisher, once extinct in Pennsylvania, concede it will eat almost any wild creature that doesn’t eat it first.
“In fishers, we’ve seen the most diverse diet, including each other, of all forest predators; there’s nothing they won’t eat,” said Matt Lovallo, wildlife biologist in the Pennsylvania Game Commission’s Game Mammals Section. “With some food items like deer, whether it’s predation or scavenging, we don’t know. We do understand that hunters have an intuitive concern about turkeys because fishers are skilled tree climbers, but birds are very limited among the food items we’ve analyzed.”
The name fisher has roots in the older French word “fichet,” which applied to the polecat, a European weasel. Known to scientists as Martes pennanti, fishers are weasel-like in appearance but larger, cloaked in dark brown to black fur, sometimes brindled with white or silver. Big males can exceed 4 feet from snout to tail tip with the heavily furred tail accounting for about a third of the total length. The sharply triangular head is topped with short rounded ears. Adult males generally range between 9 to 12 pounds, with the largest specimens nearly doubling that weight. Females are smaller.
Fishers are forest-dependent and currently range all across Canada’s forest belt, but their original distribution embraced the Great Lakes and extended southward along the Rocky and Appalachian mountain chains. As native Appalachian and Midwestern forests were cleared in the 19th century, fishers disappeared from the region. But as second-growth woodland reclaimed much of the landscape, biologists in Pennsylvania, West Virginia, New York, Michigan and Wisconsin sought to re-establish fishers in those states.
The Pennsylvania Game Commission’s Fisher Management Plan states that West Virginia released fishers captured in New Hampshire as early as 1969. New York followed in the 1980s by re-locating fishers from a remnant Adirondack population to other forested tracts. Most significantly, between 1994 and 1998, Game Commission biologists working cooperatively with Frostburg University released 190 fishers at six heavily forested sites across northern Pennsylvania. Fishers have been sighted, crushed on highways and caught accidentally in traps with increasing frequency ever since.
“Fisher reintroductions have been a success across the Northeast and Midwest, maybe at a quicker rate than we expected,” Lovallo said. “Although we released fishers in northern Pennsylvania, and they’re doing well, we believe the growing population in southwestern counties is a result of range expansion from West Virginia.”
Biologists know that fisher populations are growing and spreading within the state because they monitor legal trapping harvests, survey trappers to track incidental fisher captures and document road-kills.
The Fisher Management Plan reports that between 2001 and 2008 the number of fishers trapped incidentally rose from one to 105. The Game Commission’s Wildlife Management Unit 2C comprising mountainous Somerset, Fayette, Westmoreland, Indiana and Cambria counties accounted for nearly half of the 2008 total.
“Since we wrote that plan in 2008 the number of incidental captures has climbed to over 1,000 today,” Lovallo said.
Lovallo explained that incidental captures are fishers caught unintentionally by trappers targeting other species such as fox or raccoon, or trapped outside wildlife management units open to legal fisher trapping. Trappers are required to release these fishers unharmed if possible.
Since 2010 the Game Commission has regulated a limited trapping season (Dec. 17-28 in 2016) for fishers across 13 wildlife management units including WMUs 1B, 2C and 2D in Western Pennsylvania. Only one fisher may be taken per year and trappers must have a fisher permit.
“About 6 percent of our trappers with a fisher permit are successful. That rate has remained amazingly consistent since we started the season,” Lovallo said. “For example, [in 2015] 6,564 permit holders trapped 401 fishers in units with an open season.”
Jim Griffith, a veteran trapper from Somerset who also works as a fur receiving agent for Fur Harvesters Auction Inc. of North Bay, Ontario, has caught fishers in wide-ranging locations.
“I travel a lot buying fur and I trap in a lot of places,” Griffith said. “I’ll never forget the first thing I caught in a cable restraint in Pennsylvania was a fisher. Of course, I let it go because that was before we had a season. I carry a noose-pole and I slip the noose over one leg, stretch them out so they can’t bite and release them. Away they go.
“Being an aggressive predator, fishers are fairly easy to trap,” Griffith continued. “When the Canadians trap beaver in the remote bush they skin them on-site and take just the pelt. If a fisher gets on that beaver carcass it won’t leave it, even if it has to fight wolves.”
Griffith said signs of renewed interest in American fur from Chinese and Russian buyers, fisher pelts included, is encouraging news for local trappers and the fur market, .
“Right now, prices are as low as I’ve ever seen,” Griffith said. “But I’m optimistic and it can only go up from here. Not long ago a prime female fisher brought $200. Today, maybe $60 or $70.”
Female pelts fetch better prices than male fishers because the female’s fur is softer and silkier, Griffith explained.
Griffith’s top tip for trapping fishers?
“Use skunk scent as your lure. Fishers love it,” Griffith offered. “Around here, where you mainly find fisher is in heavy woods with hemlock or spruce where they can get red squirrels, but they have adapted well to all types of woodland.”
When asked to explain biologists’ motivation in re-introducing an opportunistic predator like the fisher, Lovallo doesn’t hesitate.
“The reality is that we had fishers in great numbers prior to the 1900s. Part of [the Game Commission’s] agency mission is to maintain and restore wildlife populations,” Lovallo reflected. “We’ve restored many such as elk, otter, eagle and beaver. Other large predators like wolves and mountain lions we’ve lost and probably never will get back, unless they do it on their own.”
Ben Moyer is a freelance writer from Farmington, Pa.
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