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Posts tagged “Mustelidae

Mink and Fisher Tracks

1-16-19 fisher and mink tracks img_2238As 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 sometimes 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. Mink weigh one to three pounds; fishers four to eighteen pounds. 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. They were both traveling on a frozen woodland stream.

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Weasel Tracks

12-24-13 weasel & stonewall IMG_9602When looking for signs of weasel– Long-tailed or Ermine (formerly called Short-tailed Weasel) – in winter, stonewalls are a good place to head. Both of these nocturnal mustelids prey on small rodents such as mice and voles, which frequent the nooks and crannies of stonewalls. In winter weasels cover a lot of ground looking for prey – the home range of an Ermine is between 30 and 40 square acres, but when food is scarce, they may travel two or three miles in one night. Often their tracks will run the length of a stonewall on one side and then back the other side. Intermittent pauses are made as the Ermine stands on its hind feet and stretches its neck out, searching the landscape for both movement and sound.

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Fisher Scat

1-23-13 fisher scat2 IMG_0098Typical 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.


Fisher Landing Imprint

fisher landing IMG_0793Although 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.


Mink Tracks & Dens

If you take a walk along a small wooded stream that has many fallen trees along its banks, you can expect to find mink tracks somewhere along it. These wetland-loving weasels dig their dens in river banks, often under tree roots, and judging from their tracks, visit them frequently. It is not unusual for one mink to have several dens which it uses as resting spots along a stream. Mink spend a lot of time in the water hunting for fish, aquatic insects and crayfish. Mink are good swimmers and can dive as deep as 16 feet. Tracks will run along the frozen sections of a stream, and then disappear into the water, only to reappear on the ice further downstream when the mink decides to travel on solid ground again. 1-8-13 mink tracks along river IMG_0175


Mink Slide

12-31-12  mink slide IMG_0004There is nothing like heading out on snowshoes to look for tracks after a major snow storm has passed. The pristine snow is often untouched, except for a few brave souls who have ventured out. Most of the mammals that are active in winter hunker down until well after it has stopped snowing, but the mink (Mustela vison) is not about to lose a night of hunting and its tracks can often be found the morning following a storm. Like other weasels, this bounding carnivore often leaves diagonally paired tracks, but unlike other weasels, its tracks are consistently the same distance (1 to 3 feet) apart. They also are most prevalent in or near wetlands. Although a fierce predator, the mink also has a playful side, much like its cousin, the river otter. Mink are known to dive under the snow and make short tunnels. Even more delightful to come upon are the slides that mink often make down inclines. If you see a groove in the snow about 3” in diameter, with paired tracks at either end, you have come upon such a slide.


North American River Otter Roll

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In addition to their winter slides in the snow, river otters leave distinctive signs year round.  Their scat is unlike most other animal scat in that it has little form and often disintegrates into a pile of fish scales.  Sometimes river otters create what are called “rolls” —  areas near water that they repeatedly visit to defecate, urinate and roll around on the ground.  If used frequently enough, rolls become so acidic that they turn black with dying vegetation.  Being a member of the Weasel family, otters possess oil glands and waterproof their fur with oil. It’s possible that in addition to marking territory at a roll, they are distributing this oil throughout their coat when they are rolling on the ground.