What Do Claw Marks Tell Us?

Claws, like hair and feathers, are made up of proteins called keratins and are characteristic of mammals, reptiles, and birds. In mammals claws evolved into a variety of forms, including fingernails and hooves, but it’s the hard, tapered appendages we consider true claws that are the focus of this post. The marks they make in tracks can tell us a lot about the lifestyles and behaviors of their owners.

The gray squirrel right and left front tracks in the photo below (direction of travel toward the left) show conspicuous claw marks. The tiny pricks made by the claws tell us they’re quite sharp, as we would expect in an acrobatic climber like a squirrel. Behind each claw mark is a toe impression, and behind the toes there is a tight group of middle pads. Two heel pads lie at the back end of the track. The combination of sharp claws and protruding toe, middle, and heel pads is what gives the gray squirrel its excellent climbing ability.

There’s another interesting feature in these prints: on the inner side of each set of heel pads there’s an impression of the vestigial fifth toe, something not often seen.

Porcupines, although not as graceful as squirrels, are also good climbers, and their feet are equipped with impressive claws. The photo below shows three sets of front and rear porcupine tracks, all heading toward the upper left. At the lower right you see a left rear track with a left front track above and to the left of it. Almost directly above those there’s a right rear print with a right front print above it. At the upper left there’s another pair of left front and rear prints. In each set the hind track is the larger of the two. The spaces between the claw marks and the oblong sole areas appear at first glance to be unoccupied– porcupine toes frequently don’t register in tracks. But if you look closely you can see faint toe impressions in the front tracks. You’ll notice that the claws of the front feet make marks a little farther forward compared to those of the rear tracks.

Fishers are also good climbers, so it’s not surprising that their tracks show the marks of sharp claws. The next photo shows the left front print of a fisher, oriented toward the left, with narrow claw gouges at the tips of the toes. But fishers don’t just use their claws for climbing–these animals are predators, and their sharp claws are essential for catching and subduing prey. The five toes, each tipped with a claw, make a lopsided crescent, and the middle pad and heel area make up the rest of the print.

Claws also come in handy for digging. Striped skunk tracks, like the left front print shown below, have prominent claw marks which extend well ahead of the toes. The claw impressions are more robust the ones in the first photo–not very good for climbing but hefty enough to make good digging tools.

The presence or absence of claw marks is sometimes considered diagnostic for track identification, but, like many aspects of tracking it’s not an absolute. The next photo shows front (lower left) and rear (upper right) prints of a gray fox, direction of travel from right to left. Gray foxes have semi-retractable claws, and prints without any claw marks, like the ones below, are common. The same goes for bobcats and house cats, which have retractable claws.

But if a gray fox needs extra grip it can extend its claws, making tracks that look like the ones in the next photo. The larger front track is on the right and the smaller hind track is on the left, and the direction of travel is toward the top. By extending its claws the animal was able to gain more purchase in the soft mud. The marks vary in thickness because of the varying depth of the tracks and movement of the toes, but the rear track shows slender grooves which are consistent with claws that are very sharp. Although not as arboreal as squirrels and fishers, gray foxes are good climbers. Their sharp claws assist not only in climbing but also in capturing prey. Claw marks are sometimes seen in feline tracks under similar conditions.

Animals with retractable and semi-retractable claws are able to draw their claws completely or partially inside their toes. But all animals, even those with robust claws, can control their position by flexing or extending the toes. The front track in the next photo (made by a coyote walking toward the left) shows beautiful impressions of the toes and the middle pad, but no claw marks.

A coyote moving at a side trot toward the right made the front (upper left) and hind (lower right) tracks in the photo below. Claw marks lie ahead of all four toes of the front track, and ahead of the leading toes of the hind track. The depths of the tracks made at the walk and at the trot are similar, but the toes were flexed enough at the faster gait to make most of the claws dig into the sand.

Partial sets of claw marks often occur in wild canines. The coyote front (left) and hind (right) prints (direction of travel toward the left) in the next photo show tiny pricks ahead of the leading toes, indicating that just the tips of the two leading claws in each print touched down.

Dog tracks, like the front print (direction of travel toward the right) shown below, are more likely to have blunt, robust claw marks that routinely show in tracks, even when walking or at rest. In the photo the claw marks have rounded leading edges due to their wider tips. In addition to the blunt claw marks, the more rounded overall shape and the outward angles of the inner and outer toes are indicators of domestic dog rather than coyote or fox.

To further drive home this point, contrast the dog print above with the red fox front track (heading toward the right) in the next photo. The red fox claw marks are slender and pointed, and they’re oriented straight ahead–or even slightly inward on the leading toes. The claw marks of the inner and outer toes are tucked tightly against the sides of the leading toes. It would be rare for a dog track to show this kind of compactness in soft mud.

There’s a explanation for the differences between the claws of dogs and wild canines. Coyotes and foxes spend their lives on the move, so their claws are constantly shortened and shaped natural abrasion. Dogs spend more time resting and less time travelling over the landscape, so their claws are not naturally worn down and must be trimmed manually. Consequently, the claws of dogs are usually longer and blunter than the claws of coyotes and foxes. Similarly, the feet of wild canines have excellent muscle tone, and this creates tracks that are tight and compact. The less fit feet of dogs spread out more and leave tracks in which the toes and claws often angle outward.

Cottontail rabbits and snowshoe hares have thick fur on the bottoms of their feet, so claw marks don’t usually show in tracks. In the photo of snowshoe hare tracks below, right and left hind tracks (oriented to the right) take up the center, a smaller left front track heading toward the left lies on the left, and part of a left hind track, also heading toward the left, can be seen at the upper right. The fur thins out somewhat in the summer, but even in July when these tracks were photographed, it was thick enough to muffle the claw marks in the rear tracks. They do show just a little at the tips of the toes in the front track.

But rabbit and hare claws are surprisingly sharp. Rabbits defend themselves with strong kicks, and the claws can inflict real damage. Claws also help the animals to grip the ground in the weaving and dodging escape maneuvers that help them evade predators. In the next photo you see two rear prints made by a leaping cottontail rabbit. The claws dug in deeply to give the rabbit a powerful take-off.

Why claw marks appear the way they do, why they’re present or missing, how they’re used by different animals–these are all questions that deserve our attention. Every track we find presents opportunities to explore this topic further.

Cottontail Rabbits

Familiar animals can be just as interesting as less common ones, and the cottontail rabbit ranks as one of our most familiar–and interesting–creatures. In the photo below (direction of travel from right to left) we see it’s characteristic Y-shaped bounding pattern: two rear tracks even with each other and widely spaced, and two front tracks behind the rear ones, more narrowly spaced with one leading the other. The right front print (the first foot to come down) lies at the right side of the photo and the left front print (the second foot to come down) lies to its left. Farther to the left you see the rear prints which form the diverging branches of the Y. I found these tracks on a highly developed barrier island on the New Jersey coast, probably not a place you would expect to find cottontails. But these animals manage to survive and flourish not just in rural and undeveloped areas but also in city parks, suburban communities, and busy commercial zones.

Although the pattern shown above is very common, it’s not the only four-print arrangement you’ll see. Sometimes a rabbit’s front feet come down together, and when this happens the prints are even with each other and pressed tightly together. Bounding squirrels make groups similar to those of rabbits, but the spacing of the front tracks is different. Whether the front prints are even with each other (the most common arrangement) or whether one leads the other, there is almost always a gap between the two prints. In the photo below the rabbit tracks are in the lower left and the squirrel tracks are at the upper right.

The tracks in the photo below were made by a cottontail bounding in deep snow (direction of travel from bottom to top), and the toes are splayed out in both front and rear tracks. Tracks like these are sometimes mistaken for snowshoe hare tracks because of their larger size.

The feet of both cottontails and snowshoe hares can spread when increased support is needed, but there’s a drastic difference between the two animals. The maximum width of a cottontail’s hind print is about 2 1/2 inches, while a snowshoe hare’s rear track can reach a width of more than 5 inches. The photo below shows a rabbit’s rear foot (seen from the bottom) in a splayed position. Note that the rear foot has only four toes.

In the photo above you can see the thick fur which covers the bottom of the rear foot of the cottontail, and the front foot is just as furry. This is why the outlines of the toes in rabbit tracks are blurry, especially in snow. The next photo shows the right front print of a cottontail (facing to the right) in mud that had dried to a perfect consistency for recording fine details. The toes are visible but not sharply defined, and the texture of the fur can be seen in and around the toe impressions. This photo also shows all five toes clearly–yes, there are five toes on the front foot of the rabbit. But counting toes can be difficult because there are also some pads which look like toes.

To help sort this out I’ve marked the toes and two of the pads in the next photo. The innermost toe is marked Toe 1, following the convention of numbering from the inside of the foot. It’s smaller than the others and often fails to register in tracks. The other four toes are larger and tipped with substantial claws, and the toe arrangement as a whole is asymmetrical.

If you’ve ever had a run-in with a rabbit’s foot you know that, in spite of the furry covering, the sharp claws can dig in quite effectively. Sometimes the claws are the only parts of the foot that make impressions, as in this photo of the right and left rear tracks of a rabbit in a hurry (direction of travel toward the upper right).

In addition to tracks, rabbits leave many other signs of their presence. You may find stems bitten off at an angle like the multiflora rose in the photo below. These angled cuts are characteristic of rabbit browsing and they arise from the anatomy of the rabbit’s jaws.

In the next photo you see the lower jaw of a cottontail with an added line representing a stem or twig. As it takes the stem between its upper and lower incisors, the rabbit positions the stem so that one end passes through the gap between its incisors and its molars. This biting technique results in an angled cut. Deer don’t have upper incisors so instead of making a clean bite, a deer grasps the stem between its lower incisors and its horny upper palate and pulls or jerks to make a rough break.

Cottontails also feed on the bark of young trees and shrubs. Their chews have a rough appearance, with bites penetrating to varying depths, as in the staghorn sumac stem shown below. Chews made by other bark feeders (beavers, porcupines, voles, and occasionally squirrels) are much neater and more consistent in depth of penetration.

Whether it’s bark, twigs, or buds, a rabbit has to ingest a lot of fiber to get at the nutritious living cells in the cambium or in the tiny leaf initials inside buds. The animals boost the nutrition they get from their food by processing it twice. After passing through most of the digestive system, waste is diverted to the caecum where it is fermented to produce additional nutrients. This material is eliminated, usually at night, as clusters of soft globs called caecotropes. We seldom see this kind of fecal matter because the rabbit eats it immediately. After passing through the digestive system again, the waste is eliminated as pellets like the ones in the next photo.

These pellets are dry and fibrous, and are normally scattered irregularly where rabbits feed and move about. Unlike the rounded cylindrical pellets of deer, rabbit pellets are shaped like slightly flattened spheres. Cottontails are now shifting to their summer diet of grasses, forbs, and flowers, but the final result will be pellets similar to those produced from woody food.

The cottontail rabbit is a thoroughly interesting creature with some impressive tools for survival. By observing its tracks and trails as well as chews, scat, and other sign, we can appreciate a creature that is beautifully adapted to its environment.

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.