Category: snow tracking

Raccoon Spring Fever

Winter is still with us, but the season is advancing and mild days are beginning to outnumber the cold ones. Raccoons have spent the frigid periods in a state of torpor, denned up in hollow trees, rock crevices, second-hand burrows, or perhaps under your porch. On warm days the animals emerge from their winter dens and roam about in search of food and mates. Their habitual use of a gait called the pace-walk gives their trails a unique and easily recognizable appearance.

In the pace-walk the tracks lie in sets of two, each set made up of front and rear prints from opposite sides. One of these prints generally falls ahead of the other (although they can be perfectly even). In each successive pair the sides of the front and rear tracks switch and, if they are uneven, the leading side also switches. In the photo above the larger hind prints lie ahead of the smaller front ones. The succession of tracks, starting at the lower right corner, is: left front with right rear, right front with left rear, left front with right rear, and right front with left rear.

Raccoons are not good at digging, and as long there’s a substantial snowpack they have difficulty getting at edibles in the leaf litter. But seeps and unfrozen streams are not only free of snow and ice–they also harbor tasty morsels like aquatic insect larvae, worms, snails, and other invertebrates. Seeps are likely to form during mild weather, and they’re usually found in the same places each year. Muddy tracks like the ones below tell us when raccoons have been visiting them.

There are two separate passages in the photo above, the upper one heading from left to right and the lower one going in the opposite direction. If you focus on the darker tracks in the middle of the photo, you can see the similarity between the patterns in the two photos. But in addition to being more irregular, the mud-on-snow tracks have a slightly different arrangement. In each set of two the larger hind foot touched down a little behind the smaller front foot. This, and the fact that the steps are shorter, tells us that the animal was going slower. The icy crust was probably slippery and the raccoon needed to be more careful with its footing.

As spring–and mud season–draws closer, raccoon tracks can be found in all sorts of wet places. When the photo below was taken a thin blanket of snow covered most of the landscape, but the silty stream margins were clear and unfrozen. The small tracks heading in both directions were made by minks, and the larger ones belong to a raccoon. There’s a pretty clear hind print near the right edge of the frame, but the other raccoon prints (one to its left and another toward the bottom of the frame) are distorted because the animal slipped in the mud. In fact the very weird track at the lower edge of the photo is actually two prints, one on top of the other. Apparently the heavier raccoon had more difficulty with its footing than the smaller minks did.

Here’s another trail made by a pace-walking raccoon on a nicely moistened sand road. The pairs of prints are a little closer together than the ones in the first photo, and the rear tracks fall slightly behind the front–both signs of lower speed. Maybe with its feet sinking slightly in the soft sand the animal chose to move more carefully, or maybe it just wasn’t in a hurry. On a mild spring day even a raccoon might feel like taking it easy.

Wild Lives Hang by a Thread

When small rodents feed above ground they usually leave obvious signs of their meals in the form of inedible remains. I love finding these because they reveal a lot about what, how, and where these animals have been eating. It’s especially exciting when I see something unusual, and that’s exactly what happened a few weeks ago. I was walking along a seldom-used (but familiar to me) trail which, at one spot, runs along the edge of a large depression in the ground, about the size of a small room. As I scanned the sunken area I saw odd scatterings of small things on the snow. Looking more closely I saw that the scattered bits were maple seeds. There were red squirrel tracks in the same areas, and many of the seeds had been opened. I knew that gray squirrels fed on maple seeds, but this was the first time I had observed evidence of red squirrels doing that.

Here’s close-up to show that the seeds were really being eaten. If you look at the one near the center of the photo (the one with the winged end pointing toward the upper left) you can see that it was opened at the base.

In our region red squirrels normally favor large stands of conifers, and the most common feeding sign consists of piles of cone scales and cores under their favorite trees. Cavities among the roots are used for food storage, and dead branches part way up the trunks offer well protected feeding perches. So my discovery of feeding sites on the snow surface, the diet of maple seeds, and the location–a mixed forest of sugar maple, red oak, yellow birch, beech, white pine, and hemlock–seemed unusual for a red squirrel. But because I was familiar with the area from warmer seasons, I knew that the sunken pit was actually an old cellar hole, probably part of a 19th century homestead. The stone walls were partially collapsed, and the rocky jumble provided perfect spaces for food storage. It appeared that this red squirrel had discovered an attractive abode.

As I explored the place I noticed another hole, shown in the photo below. This hole was bigger and looked well used–it was probably the main entry to the squirrel’s underground accommodations. But as I examined it I realized that something violent had happened. There were some spots of blood near the opening, and some of the snow around it was disturbed. There were also tracks. If you look carefully at the photo below you’ll see two small impressions in the top center. And to the left of the large blood spots some very different tracks are visible.

This called for some tracking detective work. To show the details better the next photo is a close-up. Above and to the right of the hole the snow is compressed and disturbed, and spots of blood can be seen on the left side (along with a smaller spot to the right). Although they’re faint, you can see the two small prints at the top of the frame.

The tracks to the left of the hole are particularly intriguing–the clearest ones are shaped like the letter K lying on its back. These are owl tracks, probably made by a barred owl. In an owl track the vertical stalk of the K is on the inside of the foot and the shorter angled branches are on the outside. There are two prints made by the owl’s left foot, one above and partly on top of the other. The track of the right foot is less clear, but lies below and a little closer to the hole. This means the bird was facing to the right when it made the tracks. To help you sort all of this out I’ve repeated the photo above with the owl and squirrel tracks labelled.

Here’s my take on what happened: the victim was emerging from its hole when the owl swooped down and seized it in its talons. As the owl tightened its grip the squirrel struggled and hit the snow in several places, touching the snow with its front feet to make the two prints (Sq L and Sq R). Finally the owl’s talons fatally pierced the squirrel and it held the victim on the left side of the hole, causing the bloody spots. The owl then stood on the left side of the hole, shifting its feet slightly as it got a good hold of the squirrel with its beak. It then flew off carrying its meal.

The squirrel’s life ended abruptly, and the owl beat the odds–low on average–of hunting success. Was the old cellar hole, in spite of its suitability for food storage, too exposed for a squirrel to live there safely? Will another small rodent find that spot, take up residence, and maybe even eat the stores still hidden among the rocks? And will that owl revisit the site of its good fortune, hoping for another meal? Sudden death is the way of nature, but it’s also the way of nature for animals to learn from experience and take advantage of every opportunity. I’ll be sure to go by that old cellar hole again to see if it has more stories to tell.

Ruffed Grouse Snow Beds

When the snow gets deep and temperatures go down, ruffed grouse have a wonderful way of staying warm overnight. They can’t climb down into woodchuck burrows the way rabbits do, or follow narrow openings down to warmer depths like weasels. And they don’t curl up with their tails over their heads like foxes. But they can fly, and that allows for a unique strategy. In mid-flight, a grouse tucks its wings close to its body and dives into the snow. Once submerged all it takes is a few wiggles to shape a perfectly formed and well insulated snow cave.

I found the grouse bed pictured below back in November after an unusually early snowstorm. The place where the bird plunged into the snow is on the left, and the exit side of the bed is at the lower right. The trail the bird made as it walked away extends toward the top of the frame.

Here’s the same grouse bed from another angle–the entry is now at the top of the frame and the exit is at the bottom. The cavity where the bird spent the night is located under the undisturbed snow between the two holes. If you could peer down into the lower hole you would see a chamber roughly the shape of the grouse’s body.

If you can’t picture how it all happened you’re probably not alone. One of the keys to interpreting nature’s messages is to go back in time to the beginning of the incident and work your way through to the end.

Consider what happens when you toss a ball into soft, fluffy snow. The ball disappears and leaves nothing but a small depression where it went in. It’s only when you grope around trying to find the ball that more of the snow gets disturbed. A similar situation occurs with a grouse’s snow bed. Once the bird disappears under the snow, the only sign on the surface is a depression where it went in. The grouse can’t be seen, and there’s smooth, undisturbed snow everywhere except for a hollow of tossed snow. It’s not until the next morning, when the bird wakes up and begins to wriggle forward and upward, that the snow around it is disturbed and at least one other hole in the snow appears.

In the photo above, you can see some dark material in the lower hole. A close-up shows that the dark material in the cavity is scat. Grouse typically defecate before they begin to work their way out of the their snow cave.

If the snow isn’t deep enough–or soft enough–for a plunge, grouse rest in surface beds like the one shown in the photo below. On the right side of the photo you can see a hollowed out, grouse-body-sized depression. The usual scat pile sits in the bottom of the bed, and the tracks made by the bird as it walked away can be seen heading toward the left. The scat in the surface bed (and also in the snow cave in the preceding photos) is dry and fibrous, the type of scat produced from the grouse’s normal winter diet of buds, twigs, and catkins. But in the photo below there’s another kind of scat, lying roughly in the center. This wetter, softer scat is called caecal scat, and it’s produced when a grouse eats higher quality food, such as the cambium layer of woody plants. More nutritious food goes through an additional digestive process in specialized intestinal pouches called caeca.

I marvel at the adaptations that ruffed grouse–and other creatures–have for coping with the challenges of winter. And I love the way such behaviors become more real when when I can see and understand the actual evidence. It’s worth the effort to parse out the story and see what birds and animals really do to survive.

A Gallery of Red Fox Tracks

I’m fascinated by track variation. No two tracks are ever exactly alike, even if they were made by the same animal doing the same gait on the same substrate. Sometimes variations within the prints of one species are so extreme that it’s hard to believe that they were made by the same kind of animal. This applies to all creatures, but I think the red fox is a particularly good illustration.

In the photo below you see a front print made by a red fox traveling from left to right. This is a typical track: oval in shape with finely pointed claw marks, and a curved impression–called a bar or chevron–running vertically through the middle pad. A striated texture in the toes and middle pad shows how the fur which covers the underside of the foot pressed into the mud.

The track pictured above also has some features that are found in all of our wild canines. There’s a dome in the center, and the major ridges meet at the dome to form an X shape. The toes are held tightly together and the claw marks point straight ahead.

Here’s another front print made by a red fox, again traveling from left to right but at greater speed. This time the mud was firmer, so the track is shallower and the marks of the hair are lighter. Instead of lying tightly together, the toes are spread and the claws, especially the inner and outer ones, angle outward. The bar in the middle pad is the deepest part of the track, suggesting that the horny protrusion might have served to increase traction.

A fox moving on even firmer mud and at even greater speed made the next example, again traveling from left to right. We see only the claw marks, the tips of the toes, and the middle pad bar. As in the previous photo the toes are spread and the claws angle outward.

Sometimes the fur on the underside of the foot is the most obvious feature of the track. In the next photo, made in wet mud, the direction of travel is from right to left, and the texture of the hair seems to cover the entire track except for the middle pad bar. But take a close look at the areas toward the tips of the toes, especially the two leading toes. There’s a spot in each toe impression that’s deeper and doesn’t have the striated texture. These marks aren’t just accidental artifacts–they’re real (although seldom seen) features of red fox tracks. Each toe has a small, hairless bump near its tip which can protrude through the hair to leave a mark.

There are other anatomical parts which can show up in tracks. The print in the photo below was made in soft sand by a red fox moving from left to right at high speed. The spread toes and deep toe and middle pad bar impressions should be familiar by now, but just behind and above the middle pad there’s an additional mark. This was made by the dew claw, the reduced fifth toe present on the insides of the front feet of most canines. And to the left of that and straight back from the middle pad there’s a shallow indentation made by the carpal pad, a knobby protrusion found higher up on the back of the front leg. This is another feature found on foxes, coyotes, and domestic dogs.

Dewclaws and carpal pads only show in tracks if the lower leg joint (it’s actually the carpal joint) is well flexed or the foot sinks down into the substrate. The print pictured above had some of both–the foot sank into the sand and the galloping gait caused significant flexion in the carpal joint.

I’ve been focusing on tracks in mud and sand because they show track details so beautifully, but snow can be just as revealing. The red fox that made the prints below was traveling from left to right. There’s a nice bar in the middle pad of the front track (at the lower left), and as we expect in the red fox, the rear track (at the upper right) has a smaller middle pad with no bar. The dome and canine X show clearly in both tracks. Small depressions at the tips of the toes of the rear track show where the hairless protrusions (the same ones seen above in the wet mud) pushed deeper into the snow. In dry, fluffy snow like the substrate in the photo below, the fur on the undersides of the feet doesn’t leave distinct marks. Instead it has the effect of blurring the outlines of the toes.

Track variants can be puzzling, but they can also lead to better understanding of foot anatomy and animal movement. So when you’re perplexed by an unusual print take a breath, focus on something different for a moment, and let the pieces of the puzzle fall into place at their own speed. It will be well worth your time.

Spring Fever among Woodchucks

If you think you have it bad, just consider the woodchuck. The males emerged from hibernation weeks ago only to find the ground covered with snow. There wasn’t much to eat, and the weather wasn’t very spring-like. But no matter–they were more interested in procreation than food or comfort, and they spent their time searching out burrows occupied by females. Upon finding a receptive female the male entered the den and copulated with her, then moved on in search of another one. With nothing much to eat the roaming males, which may have dropped up to 1/3 of their body weight during hibernation, lost even more body mass. Meanwhile, the female woodchucks remained underground and got a few more weeks of sleep.

This delayed emergence is important because, like the males, female woodchucks have already lost weight during hibernation and losing even more would impair their ability to give birth to healthy young. Their appearance above ground coincides with the onset of new spring growth and their condition improves rapidly.

I found the den pictured below in early March. A few inches of new snow covered about a foot of denser old snow, which made for nice tracking. There weren’t any tracks beyond those shown in the photo, so it looked like the animal came out, took a look around, and then went back into the burrow. The mud-on-snow tracks are remarkably clear–check out the right front print just to the right of center.

Finding such unmarred tracks around burrows becomes less likely as the season advances and the animals make more forays to and from their winter refuges. The photo below, also from early March but taken a few years ago, shows the muddy and partially melted evidence of several trips. In both of these cases the weather was still pretty cold and there was a substantial snowpack, so these were most likely males in the throes of spring (or rather mating) fever.

As winter loosens its grip woodchuck tracks start becoming more widespread in fields and forest edges. In the photo below the direction of travel is from the lower left of the frame to the upper right, and the impressions form a zig-zag pattern. Each angle of the zig-zag is composed of two


tracks, the rear positioned roughly on top of or close to the front track from the same side. These are the characteristics of the indirect register walk, the woodchuck’s most common gait. Starting from the lower left, the sequence in the photo above is right hind on right front, left hind on left front, right front with right hind just ahead, left hind on left front. To the right of the first set of left front and hind there are some gray squirrel tracks heading in the opposite direction.

By the way, woodchucks are also known as groundhogs, but I prefer the name woodchuck, because the word derives from one of its Native American names. Woodchucks weren’t as common in pre-colonial times as they are now, but their populations would have been concentrated around cultivated fields so they would have been familiar to Native Americans. They still thrive in agricultural landscapes, and are sometimes seen as pests. From an ecological point of view they are actually beneficial. Woodchuck excavations help to turn over and aerate soils, and their burrows provide homes for many other animals.

The photo above shows a burrow I found after a very cold night. Rabbit tracks led both in and out, but this hole wasn’t dug by a rabbit. Unlike European rabbits, which construct extensive tunnel systems called warrens, our cottontails don’t dig burrows. They get along just fine without underground housing, unless it’s very cold. When that happens they find shelter, and that shelter is often a woodchuck burrow.

An Encounter with a Fisher

Sightings of wild mammals are generally rare, and when they do occur it’s usually just a quick glimpse of the tail end of the animal as it flees at top speed. So my recent encounter with a fisher was doubly unusual. I was walking downhill on a sloping section of forest road (Hammond Hill Road in Hammond Hill State Forest for those who know the area). That part of the road is straight so I could see pretty far down the hill, and I suddenly realized there was a dark animal moving around on the road far below. I froze, not sure at first what kind of animal it was and hoping it wouldn’t realize I was there. It didn’t–in fact it actually began coming up the hill toward me. As I got a better view of its elongated body, short legs, and long fluffy tail I realized it was a fisher. I watched as it moved in a completely relaxed manner–apparently unaware of my presence–and marveled at its beauty. I was afraid if I made a move to get out my camera the fisher would take off, so I didn’t dare try for a photo. But here’s a good photograph of a fisher obtained from the Vermont Center for Ecostudies (https://vtecostudies.org/blog/walk-with-the-fisher-on-outdoor-radio/).

Photo courtesy of the Vermont Center forEcostudies

The fisher continued to move uphill in my direction at a steady bounding gait, with an occasional pause to look around. When less than 50 feet separated us, it suddenly realized I was there. It stood up on its hind legs, stared at me for a few seconds, and then bounded off into the trees.

Of course I immediately went to look at the tracks. Because the snow was dry and fluffy most of the prints weren’t clearly defined, and the cloudy conditions made things even harder to see–and nearly impossible to photograph. But there was a spot farther down the hill where the snow was firmer and the track details showed up better. A set of four prints from that part of the trail is shown in the photo below (direction of travel from right to left). The pattern

Track sequence, starting from the right: right front, left front, right rear, left rear.

resembles the bound of a cottontail rabbit: the two front tracks are narrowly set behind the rear tracks, and one (the left front) leads the other. The rear tracks are more widely separated and almost even with each other. Typical mustelid structure shows in the prints: the five toes are arranged in a lopsided crescent and the middle pads form a smaller crescent behind the toes.

That was only one of several different gait patterns I saw as I backtracked along the fisher’s trail. In true mustelid fashion the animal had been very flexible in the way it placed its feet. Rather than showing the rather poor photos from that day I’ll illustrate two of the variations I saw with shots that I took on other days (the direction of travel again is from right to left). As in the opening shot the four tracks in the photo below are well separated, but the rear prints are staggered rather than even with each other, and one is positioned slightly behind the leading front print.

Track sequence, starting from the right: right front, right rear, left front, left rear.

In the next shot the left rear foot came down on top of the left front, leaving a pattern that looks at first like there are only three tracks. But in the heel area of the middle impression there’s an inner ridge and a wider area of disturbance to its left, showing that two feet did actually land there.

Track sequence, starting from the right: right front, left rear on top of left front, right rear.


In addition to those two there were other variations–changes in the leading front or rear foot and slightly different placements of the second and third feet to hit the ground–but to my eyes the fisher’s bounding movement appeared to be uniform and unvarying. Except for momentary pauses it moved steadily uphill with the gently arching leaps that are so typically mustelid. One difference did stand out, and that was a variation in the leap lengths: the four-print patterns that matched the one shown in the first photo were separated by slightly longer distances than the patterns shown in the second and third photos. The fisher apparently wanted to move faster, and I suspect that the more even placement of the rear feet in the first photo delivered more power and enabled longer leaps. But there were many variations in the patterns that didn’t involve any changes in leap length, so there must be other factors that cause a fisher to vary the way it places its feet. I can only imagine the subtle interactions that go on between the animal and its surroundings. I hope that with further study of fisher trails, and maybe even some additional encounters with fishers, I’ll be able to understand more of the puzzle.

The Allure of Scent Marking

Deep in the coldest months of winter, when you’d think every animal is single-mindedly focused on survival, some predators are being distracted by an equally compelling urge–mating. Even as the snow flies, time spent hunting decreases and behaviors connected with reproduction become more predominant. For the tracker one of the best signs of this change is an increase in scent marking. I followed a red fox trail recently, and she was detouring to urinate on raised features like this stump every 500 feet or

so. I say she because the arrangement of tracks and the placement of the urine could only have been done by a female fox. In the photo the small spots in the left half of the stump are urine (you can ignore the dark chunk of bark near the center). The fox came in from the lower left, paused on the upper side of the stump to pee, and proceeded towards the upper right. The more deeply impressed track marked SF was made by the supporting rear foot (the left) while the right rear was raised. During mating season red fox urine has a strong, slightly skunky–but not unpleasant–odor that is obvious even to us smell-challenged humans. So as I followed the trail the air was perfumed with fox musk.

My dog Banjo (dogs are great teachers for wild canine behaviors) demonstrates the technique in the photo below, supporting her weight on her right rear foot plus the two front feet and positioning her left rear leg up and forward. You can actually see the urine squirting downward under her rear end.

Male canines also raise a rear leg when they urinate, but the leg is held out and back, and the urine goes out to the side rather than downward. I don’t currently have a male dog so I can’t show you that, but I’m sure you can imagine the posture. A male coyote, traveling from left to right,

made the scent mark above, supporting its weight on the right rear foot (the track at the lower center) and shooting the urine sideways onto the upper part of the stump. Coyote urine has a mild odor and isn’t nearly as detectable by humans as fox urine is.

Bobcats also feel the mating urge in the winter, and again, those who have house cats, especially males, may have observed the technique. A male bobcat left its signature on the log in the photo below, coming in from the top of the frame, depositing its message, and leaving at the lower left.

It first gave the log a good sniff (revealed by the front print facing the log), then turned so its rear was facing the wood and sprayed urine backwards. Here’s the photo again with the tracks marked.

S denotes where the bobcat placed a front foot as it sniffed the log. RH, LH, RF and LF show the four feet in a squared posture as the cat faced away from the log and urinated backwards. Bobcat urine, like house cat urine, has a strong odor of ammonia, so if you had been there to sniff the side of the log you would have detected the cat-box odor. Female bobcats also scent mark, mostly downward from a squatting position.

Scent marking by wild canids and felids continues through pair formation, den preparation, and birthing. Soon after that hunting begins to regain its importance as the pressure to provide food for the growing young increases. But the timing of reproduction isn’t accidental. The earlier onset of predator reproduction means that their greatest need for food coincides with the greatest abundance of prey animals, which mostly mated in early spring and multiply during spring and summer.

The Ups and Downs of Snowshoe Hares

Snowshoe hares are having a banner year. In early December I spent some time in the western Adirondacks, and it seemed like there were snowshoe hare trails everywhere. A bounding hare-like its cousin the cottontail rabbit-typically leaves sets of four prints in Y shaped arrangements. The two larger rear prints are usually even with each other and widely spaced while the smaller front prints are behind the rear, staggered,  and placed along the center line of the trail. 

In the photo at the right (direction of travel from right to left) the hind tracks are the larger and somewhat triangular prints on the left side. The right front print is near the center of the photo and the left front print is behind it toward the right edge of the frame.

The hare that made the tracks above didn’t sink very far into the snow, so it’s easy to see all four prints. But when temperatures stay low and the snow keeps falling there may be a foot or more of light, fluffy stuff on top that doesn’t offer much support. That’s the way it was during my recent Adirondack visit. Even the snowshoe hares were sinking deeply at every leap, and their landing patterns didn’t look the same.

In the photo at the left a bounding hare traveled from bottom to top, leaving a triangular hole each time it landed. At each landing the front feet plunged into the snow at the narrow lower part of the triangle. The more widely held hind feet–each foot spread out laterally for maximum support–landed just past the front feet to form the wide upper part of the triangle. The width at the widest part of these craters can approach twelve inches.

Snowshoe hares, like cottontails, tend to use the same travel routes repeatedly. This creates trails that offer firmer footing and easier movement, like the one shown at the left. I’ve read that these trails help the hares escape from predators, but I’m not sure about that. Maybe the predators can move more easily as well.

Snowshoe hare populations are known to go through cycles of abundance and scarcity. These cycles are especially pronounced in the Boreal forests of Canada, where population numbers of the Canada lynx are closely tied to the abundance of hares. The Adirondacks host a greater variety of both predators and prey–although there are no lynx–and population fluctuations don’t reach the same extremes for either prey or predators. But when hares are more abundant than usual, as they seem to be in the western Adirondacks this winter, young fishers, coyotes, and bobcats–the main predators of snowshoe hares in this region–are more likely to make it through their first winter. I hope to visit the same locations over the next few months, and I’ll be paying special attention to the tracks and signs of all the animals in the web of relationships that includes the snowshoe hare.

Lessons from Flying Squirrels

The weather has been unusually cold and snowy for early November, and there have been days when conditions were perfect for seeing detail in the tracks of small animals–an icy base with about half an inch of new, soft snow on top. On one of those days I went to a location where I had seen flying squirrel trails in past years, and I found some beautifully detailed prints. In the photo on the right (direction of travel to the right), the right rear track is at the bottom of the frame, and the right front is just above it. The other two prints are at the top, the left rear just behind the left front. The toes  and middle pads show up nicely in both front and rear tracks. The heels of the rear prints made impressions, and the paired heel pads of the right front track  can also be seen.

Now compare the shot above with these chipmunk tracks, photographed on the same day and arranged almost identically except that the left front track is just below the left rear. There’s a similar amount of detail, with toes and middle pads clearly visible in both front and rear feet and the paired heel pads showing in both front feet. I had hoped that if I found really detailed tracks I would see features that would separate chipmunks and southern flying squirrels, but to my eyes there are no appreciable differences between the tracks in the two photos. The dimensions are similar as well: both sets of prints have a trail width (the distance from the right edge of the right rear print to the left edge of the left rear print) of 2 inches, and the length of the front track is 9/16 inch for the flying squirrel and 5/8 inch for the chipmunk, not significantly different. So how did I know that the tracks in the first photo were made by a southern flying squirrel, while those in the second belonged to a chipmunk?

The answer came from the differing trail patterns. Southern flying squirrels have flaps of skin (patagia) that connect the front and rear legs all the way out to the ankles, so they move differently from chipmunks (and also from tree squirrels, for that matter). The front tracks of a bounding southern flying squirrel are set almost as wide as the rear, and they are usually in front of, or occasionally between, the rear tracks. Because of the skin flaps, flying squirrels are not as fleet-footed on the ground as other small rodents, so their leaps are shorter. Compare the southern flying squirrel bounding trail in the photo above (traveling from bottom to top) with the next photo of a trail made by a chipmunk (traveling from top to bottom). In its normal traveling bound the chipmunk consistently places its rear feet ahead of its front, and its leaps can be much longer than those of the flying squirrel. Of course chipmunks do sometimes make short leaps, and they do sometimes place their front feet between (as in the second photo of the blog) or ahead of the rear. That kind of pattern in a chipmunk trail is an indication of a break in the rhythm, while it falls withing the normal bounding pattern for a southern flying squirrel. (By the way, neither of the bounding photos came from the day I took the close-up shots, but they illustrate the trail patterns I saw that day.)

More snow changes everything. All bounding animals switch to what I call a double-register bound when their feet sink deeply into the snow. The trail pattern consists of sets of two impressions more or less side-by-side, created when the rear feet come down in the holes just made by the front feet. For an animal the size of a flying squirrel even a few inches of soft snow can be enough to change its gait pattern from its normal bound to a double-register bound like the one in the photo at the right (direction of travel from lower right to upper left). The relative positions of front and hind prints no longer apply, but trail width can still be measured, and this trail had a trail width of 2 1/8 inches, squarely in the range for the southern flying squirrel. A chipmunk trail would have had a similar trail width, but the trail pictured above was made during a long stretch of cold weather. Chipmunks wait out winter’s coldest periods in a state of torpor in their underground refuges, while flying squirrels come out regularly even in frigid temperatures.

The Graceful and Adaptable Mink

The mink is one of my favorite animals, so I’m always happy to find tracks like these, from a Tracking Club outing a few weeks ago. The marks made by the toes (5 on both front and rear feet) are small and oval or tear-drop shaped, and they form lopsided crescents around the middle pads. The claws may show as tiny pricks or as pointed extensions of the toes. The smallest toe lies on the inside of the track and farther back than the other toes, and it doesn’t always show. The mink that left these impressions was fidgeting around on a patch of stream side mud (the water is visible at the upper left) and the clear prints are mostly from the front feet.

But the beauty of mink tracks goes beyond the delicacy of individual prints–the trails that these animals make are equally fascinating. Here are the two front and two rear tracks of a mink arranged in a pattern often seen in mink trails. The first track at the lower right is the right front, and the last one at the upper left is the left rear. In the center of the photo the left front is on the left and the right rear is on the right. The animal was loping from the lower right to the upper left, and the order of footfalls was right front, left front, right rear, left rear. A mink traveling on stream ice a few winters ago left a string of similar four-print patterns. In the center of each grouping the left front print is slightly behind instead of ahead of the right rear, but otherwise they’re a good match with the previous photo, with the same direction of travel and order of footfalls. Notice how the four-print groupings are separated by spaces with no tracks–a characteristic of lopes and gallops. When I see trails like this I can picture the mink doing its easy, ground-covering lope, its spine curving and extending with each landing and take-off. I couldn’t find a video of a loping mink that I liked, but I did find one of a fisher (closely related to the mink) doing the same gait. Watch it here.

Stream edges are great places for finding mink tracks, especially if there are  roots or debris piles where prey animals can hide. The patch of sand visible in the center of this photo captured the tracks of a mink that was hunting in the surrounding tangle of logs and branches, deposited by a big flood several years ago.

But minks are resourceful when it comes to finding food. Last spring I was walking by an old log landing and I noticed a drying mud puddle. I’m always interested in mud so I went over to take a look, and to my surprise found mink tracks around the edges. There was a small pond nearby, but otherwise not much water, and I didn’t understand why this place–just a big area of bared mineral soil with a few mud puddles–would interest a mink. But the tracks were plentiful and very clearly mink. In the photo on the right the mink tracks run from lower left to upper right, and the big prints in the middle belong to my dog. As I moved around the edge and pondered, the mystery resolved itself. A leopard frog leaped from a grass clump into the water, then another one jumped, and then several more. Some enterprising mink had discovered the puddle, perhaps just as the tadpoles were transforming into frogs, and made use of the easy dinner. There were still plenty of frogs left to spend their summer feeding in the surrounding forest, overwinter deep in the soil, and then mate and lay eggs in the puddle next spring.