Fishers Looking For Love

My skis chattered over rough snow on the Valhalla Ski Trails that are perched on the spine of the Bayfield Peninsula. Several loops zoom from dark stands of pines through the lacy twigs of hardwood forests. The groomer had been out earlier that day, but in places where the previous day’s warmth had turned icy overnight, the surface had crumbled.

Still, the snow had enough give that when my ski buddy shouted “Check out these tracks!” I could snowplow to a stop and go back to look. Around the office, we’ve been asking each other the question, “If you could instantly be great at any Olympic sport, which would you choose?” Several people have mentioned skiing, but that doesn’t appeal to me. I prefer to ski slow enough that I can stop and look at tracks.

Male fishers travel widely in search of females in late winter and early spring. This one left a 1-2-1 loping pattern in soft snow at the Valhalla Ski Trails. Photo by Emily Stone.

These tracks went loping off through the forest in a winding trail. Unlike a wolf or a lynx, who usually walk or run in an even pattern of left, right, left, right, this Being had made groups of three or four big tracks separated by longer intervals. Each track showed five toes with pointy claws. This is the classic 1-2-1 lope pattern of a fisher. One front paw landed first, by itself in the back of the group (1). Then the other front paw and one hind paw landed side-by-side in the middle (2). Finally, the last hind paw left a single track at the front of the group (1).

From the depth that the toes had clawed into the snow, and also the smooth surface on the bottom of the tracks, we determined that this big weasel had been wandering around yesterday afternoon or evening, when the snow was still soft. Those long claws, when used in combination with rear ankle joints that can rotate 180 degrees, allow fishers to climb down trees headfirst!

Female fishers may be climbing trees this time of year as they look for a good place to have their young. Hollow trees are common den sites, as are rock crevices, slash piles, abandoned beaver lodges in dry ponds, and old porcupine dens. Inside the female, eggs fertilized last spring have only just begun to develop. A few kits will be born—blind and helpless—in late March to early April. Just a week or two later she will come into estrus and leave the den briefly to mate, but the new embryos won’t develop further until next February. Meanwhile, she will spend four months caring for the kits.

We continued skiing through the mature forest, admiring big trees and snags that the Forest Service has left for wildlife habitat. Fishers prefer closed canopy forests with lots of fallen logs. The cutover era, when most of Wisconsin’s forests were logged and then burned, had a devastating impact on fishers. Not only did these events remove their habitat, the influx of people led to overharvesting fishers for their fur. Fishers were absent from Wisconsin by the early 1900s.

I’ve heard a story that it was foresters who lobbied for the reintroduction of fishers because the number of porcupines had increased so much that they were nibbling the bark off too many trees. Porcupines are well-defended against predators, but the low, slinky posture of fishers allows them to dart in and attack a porcupine’s face repeatedly. Once the porky is incapacitated, a fisher will flip them over and access their unprotected belly. Fishers also eat squirrels, and compete with lynx for snowshoe hares. When fishers eat mice and voles, spores from truffles and other fungi in the preys’ stomachs also pass through the fisher’s digestive tract and may be dispersed far and wide.

Despite their name, fishers don’t really eat fish. The word seems to come from a European term “fitch,” which refers to a similar animal on that continent. The ancestors of fishers likely migrated to North America from eastern Asia between 2.5 and 5 million years ago. Sometimes called fisher-cats, they are not felines, nor have the rumors that they commonly eat cats stood up to scientific inquiry.

On the far side of the ski trail loop, we coasted past another loping line of fisher tracks, almost certainly made by the same animal. Early spring is when male fishers travel widely in search of mating opportunities. I often see their tracks in the softening snow as they tour their 9-15 square mile home ranges that overlap the smaller territories of several females.

Whether the Wisconsin DNR decided to reintroduce fishers for porcupine control, or just because they belong on the landscape, the recovery effort that began in the 1950s was successful. By the 1980s there were enough fishers to allow trapping again, and today their population in the state is estimated at over 10,000. Even so, I rarely see these dark brown weasels, except on my trail camera, or in my imagination as I watch their tracks lope off into the snowy woods.

While there are an estimated 10,000 fishers in Wisconsin, I rarely see them in the wild. Trail cameras are a much easier way to catch a glimpse of one. Photo by Emily Stone.

Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and at your local independent bookstore, too.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is now open with our exciting Growing Up WILD exhibit. Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.