I have never heard of this particular fisher hunting technique, nor have I seen or read about it before, but there’s no denying that a fisher made these marks in the snow and that they tell the story of how it captured a mouse or vole. It’s likely that the fisher could hear or smell that the rodent tunnel in the subnivean layer was occupied. It looks as though the fisher methodically scraped snow towards the center of the circle, going completely around the tree in an attempt to trap and/or expose the mouse or vole within the circle. It succeeded in opening up the rodent tunnel (the hole is in the dead center of the photograph), and if the tiny droplets of blood on the snow near the hole are any indication, was successful in capturing its prey.
Typical fisher scat is anywhere from ¼” to ¾” in diameter, very dark and often quite twisted. It’s not unusual to find just a small amount of scat deposited, as fishers can control the amount of scat they use to mark territory. This scat is a bit atypical, in that it is segmented and not twisted, and there is an ample amount. A close look reveals the dark, stiff hairs and quills of a porcupine, likely the fisher’s most recent meal. Look for fisher scat on raised surfaces such as stumps or at the base of old trees, where fishers occasionally make latrines.
Although fishers are agile climbers, they catch most of their prey and do the vast majority of their traveling on the ground. Occasionally, often in coniferous forests or if threatened, they will climb a tree. When they decide to come down, they jump and land on all four feet. If there is snow on the ground, the fisher leaves an impression, the clarity of which is determined by the depth and relative dryness of the snow. In the wet snow we’ve had recently, a fisher’s four feet left clear tracks when it landed on the ground, and you can even see a slight depression where its head touched the snow. Sometimes the tail is also evident. In this photograph, you can tell the direction in which the fisher intended to head without even looking for further tracks, just from the angle of its body.
Some of the most common tracks in the woods of central Vermont are those of fishers. These members of the weasel family, although known for their agility in trees, travel extensively on the ground. Fishers have been known to cover 28 miles in two days in search of food. They may be active day or night, and especially at dawn and dusk. If you persevere long enough while tracking one, you will be rewarded by some kind of sign in addition to tracks, be it a trampled conifer sapling, or a stump or a log where a fisher has marked its territory by depositing urine, scat or both. Occasionally you will come upon a bed, often right next to the base of a tree, where the fisher has stopped to rest. More often than not, their typical dark scat can be found in these locations.
As members of the weasel family (Mustelidae), fishers and mink have five toes on both front and back feet. Often all five digits do not register, but in prime tracking snow, you can often see them. Typically, mink tracks are found near a body of water, and fisher tracks are found under a canopy, not in the open. Where you have both water and trees, it’s possible to see signs of both animals. In general, the larger the animal, the larger its tracks. In this photograph, the mink tracks (smaller, in the middle) are heading towards the top of the photograph, and the fisher tracks (top most and bottom most) are heading towards the bottom of the photograph. Although not pictured here, both of these carnivores engage in snow sliding, much like their cousin, the river otter, and the resulting grooves are occasionally found when the snow is a bit deeper than it is now.
Contrary to their name, fishers seldom eat fish. While they prey on a wide range of animals and even plants, their preference is for small mammals (80% of their diet), snowshoe hares and porcupines. Because fishers are well equipped to kill porcupines, and because there is little competition for them, porcupines are an important prey of fishers –up to 35% of fisher diet samples contain the remains of porcupines, as this photograph of fisher scat attests to. There is no mistaking the bumpy porcupine foot pads (and quills)!