Fishers, with their nimble ability to climb trees, prey on squirrels and even porcupines, but they’ll eat just about anything.
Pennsylvania’s deer hunters may be in for a special treat next week.
This year, more than last, and more than the one before that, and more than at any time in a century, really, they could perchance catch sight of a fisher.
They’re second-largest member of the weasel family, smaller only than otters. A female might go 8 to 10 pounds, a male twice that.
“They’re about the size of a large housecat,” said Matt Lovallo, chief of the game mammals unit of the Pennsylvania Game Commission.
And they’re on the increase.
Fishers are native to Pennsylvania, but were gone by the early 1900s, he said, yet another species that fell victim to widespread logging and unregulated hunting. The last officially on record as being taken in the 20th century died in Lancaster County in 1921.
That was it for the next 70-plus years.
They’ve come back in a big way since, though. In 1969 West Virginia wildlife officials released 23 fishers. They spread up into Pennsylvania on their own via the Laurel Highlands.
Later, starting in 1995, 190 fishers were released in northcentral Pennsylvania. They came from New York and New Hampshire.
In the years since, the two populations have met and spread – geographically and numerically – to the point that each day someone somewhere in Pennsylvania probably catches sight of a fisher for the first time, Lovallo said. Their numbers have really taken off since 2008, he added.
“So it’s a pretty exciting time,” he added.
Deer season, when so many people are in the woods, will provide opportunities for sightings for many.
That’s partly because fishers are active all year round, Lovallo said. Their metabolisms race to such a degree that they are out hunting all the time, no matter the weather, he said.
“From our radio telemetry studies we know that even in the coldest winter conditions they’re out foraging, often in daylight hours,” Lovallo said.
They’re not particular about what they eat either. Lovallo called them “opportunistic, highly adaptable and highly efficient foragers.” Studies looking at their stomach contents here in Pennsylvania have turned up bits of everything from insects and fruit to cottontails and squirrels to birds and bird eggs.
Researchers have even found pieces of other fishers – feet were especially common – though it’s not clear if fishers prey on one another or scavenge dead ones, Lovallo said.
The one thing that is consistent is where the fishers are found.
At one time, it was thought that they needed large stands of mature timber to survive. That’s proven not to be true, Lovallo said.
“What we’ve learned through habitat studies is that it may not be as important what’s in the canopy in terms of tree species composition as what’s on the forest floor,” Lovallo said.
“We’ve learned that dense understories and particularly an abundance of coarse, woody debris is important and valuable for fisher populations, primarily because they support a diverse and abundant population or community of small mammals.”
If they find that in the big woods they do well, Lovallo said. But they can do just as well in such cover in the suburbs, he added.
Pennsylvania has had a fisher trapping season since 2010. This year’s season is set for Dec. 19-24. That’s the most conservative season of its kind in North America, he added.
Participation has been increasing – there were 2,886 fisher trappers in 2010, compared to 6,564 last year – as have harvests. Trappers took 152 fishers in 2010, 401 last year, which was down from a record 443 the year before.
The number of fishers taken per 100 permits has remained pretty consistent, though, Lovallo said, suggesting populations continue to do well.
“The current fisher harvest is having little to no impact on the upward growth of our fisher population,” Lovallo said.
“We’re getting really close to having a truly ubiquitous fisher distribution in probably all forested habitats throughout Pennsylvania.”
For all that, they’re probably not impacting any one particular prey species, he said. Their diets are too varied for them to really hurt game populations, he said.
Wildlife management unit 2D gave up more fishers than any other last year, followed by 2F, 2C, 4D, 3D, 4E, 2E, 2G, 3B, 3C, 3A and 2H, in that order.
