After a long absence fishers have returned to our northeastern forests and made themselves completely at home. These medium-sized members of the mustelid family can travel miles in a single day at their habitual loping gait, shown in the photo below (direction of travel toward the upper right). At the lower left you see four separate prints; the sequence, starting at the left, is left front, left rear, right front, right rear. The next set is also made up of four prints, but it looks like just three because the left rear fell mostly on top of the right front. By the way, the arrangement you see on the ground is not the same as the order of footfalls, which is left front, right front, left rear, right rear for both groupings.
The addition of fishers is a benefit for our ecosystems, but aside from that, having fishers in the woods makes for some interesting tracking. If you follow fisher trails you may come upon spots, such as the piece of wood in the next photo, where the snow has been strangely disturbed and smoothed. A fisher came in from the left and rubbed its belly over the wood, depositing chemical signals from the scent glands in its skin. Fishers usually choose protruding objects for marking, and the process can involve some amazing bodily gyrations. Rubs are sometimes topped off with a little urine or scat, and the finished creations serve to communicate territorial claims or availability to potential mates.
Fishers are drawn to trees, and when travelling they often move from one tree to the next to investigate for the presence of squirrels, one of their principal prey items. So it’s no accident that the fisher that made the trail below headed directly to a tree. The animal was travelling at a double-register bound, leaving a string of paired impressions separated by relatively long spaces. A bounding fisher covers the spaces between tracks in graceful arcs and lands on its front feet almost, but not quite, simultaneously. As it lands it draws its body into a tighter curve, and the front feet lift off just as the hind feet come in to land where the front feet were. The animal then takes off from its hind feet in another arcing leap. By bringing the hind feet into the same holes made by the front feet the fisher conserves its energy when travelling in deep snow. Note that one of the impressions leads the other, and that the two hollows are close together and relatively large. Squirrels, and most other animals, also alter their gaits in deep snow for more efficient movement. If a squirrel had bounded toward the same tree its trail would also be a sequence of double impressions, but each hollow would be smaller and the two would be mostly even with each other and more widely separated.
Fishers are expert hunters. It’s rare to find a kill site, but it’s not uncommon to find a trail that reveals a successful hunt. In the photo below the prints of a bounding fisher go from left to right across the middle of the frame. Above each group of tracks you can see a slightly curved line carved into the snow. The fisher was carrying a prey animal in its mouth, probably gripping the back of its victim. Something dangling to the side, a foot or an ear, brushed the snow each time the fisher landed. Such marks can fall outside the trail or within it, but they always occur at regular intervals in synchrony with the predator’s gait. Random gouges made by wind-blown leaves or other objects may fall in or near a trail, but they don’t repeat in synchrony with the track groups the way the marks of a prey item being transported do.
Winter is mating season for fishers, and when a male and female come together the story is recorded in the snow. If you come across a wild-looking collection of tracks like those in the photo below check for size differences. Male fishers are generally almost twice as large as females, and their tracks reflect their greater size. In the photo, male and female tracks are mixed together near the tree, but the smaller tracks of the female can be seen by themselves at the lower left. This female was probably receptive (not always the case) because their prints were mixed together over a wide area.
Looking carefully I found some nice prints, shown in the next photo, which showed the size difference. A small female track lies to the left of a much larger male track, both heading from left to right.
I’ve already mentioned the fisher’s affinity for trees. The animals are excellent climbers, able to scale vertical tree trunks to get into hollows sheltering squirrel nests or attack porcupines clinging to upper branches. A fisher’s rear feet can rotate 180 degrees, allowing it to grip with its rear claws when descending head-first. You may find fisher trails that lead to and end at trees the way squirrel trails often do. And sometimes, if the snow is deep and soft, you might find a place where a fisher skipped the downward climb and leapt from the tree trunk. In the photo below a fisher jumped from a tree outside the frame at the upper right and landed in the upper right quadrant. There’s a rectangular hole made by the fisher’s body with four pits at the corners made by its four legs. To the right of the hole its tail made a curved gouge. Its first bound can be seen in the lower left quadrant.
When trailing fishers you might have to keep at it for a while–it’s amazing how much distance the animals can cover in a single hunting or mate seeking episode. But if you’re persistent you’ll be rewarded with fascinating evidence of of their daily activities.