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.

Bringing Home Dinner

When we come upon a site where a predator killed a prey animal, we’re able to see in detail the interaction between hunter and hunted. But finding such a site is a rare. It’s more common to find the trail of a successful hunter carrying its prey, and this also makes for fascinating study. To understand such a trail we must pick out the crucial evidence from the other disturbances that occur in animal trails. Let’s start with a fairly straightforward example.

In the photo below you see a trail made by a fisher loping from left to right. There are three typical fisher track groups, each group a place where the fisher landed and then took off. Above each track group you can see a curving gouge in the snow made by something the fisher was carrying. But what exactly was being carried? Could it have been a stick? Not likely, based on the length of the trail involved (it went on for quite a distance) and the consistency of the patterns. There’s also the fact that the marks are curved, suggesting that the item being carried was swinging slightly. (If you visit a place where dogs have been playing with sticks you’ll see how different it looks when a stick is being carried.) The predator would have been gripping the body of its prize, and something that extended to the side would have touched the snow at each landing. The curving marks are actually made up of two parallel lines, and these lines seem too widely separated to be claw marks from a dangling foot. Their size and positioning do seem about right for the tips of wing feathers, suggesting it was a bird. If it was a bird it couldn’t have been large, since it only touched the snow at the low points in the fisher’s bounding gait. A turkey would be much too big, and even a grouse would probably have left more traces in the snow. Perhaps it was something the size of a blue jay or a junco.

A short-tailed weasel bounding from upper left to lower right made the trail in the next photo. The trail consists of paired track impressions, a common pattern for small mustelids. To the left of each set of weasel prints there’s a thin, slightly curved line in the snow. There’s also a shorter and wider mark just ahead of the weasel tracks. The thin lines are the right size for a tail, and the wider depressions could have been a foot. Given the small size of a short-tailed weasel, it’s likely that the predator was carrying something equally small. A white-footed mouse seems unlikely, because its long tail would have made a longer stroke in the snow. My guess is either a meadow vole or a woodland vole.

The next photo shows the tracks of a fisher loping from right to left, and just below the tracks you see a wide groove. Below that groove you can see several lighter lines. These finer marks aren’t completely parallel with the deeper groove, so the deep groove and the fine lines must have come from separate body parts. The wider groove seems too deep and even to be something as light as a feather–was it a tail or perhaps a thickly furred foot? The finer lines could be the marks of dragging claws. This example is less clear than the two preceding ones, but I’m inclined to think the prey item was a mammal, perhaps a rabbit.

Now to some examples of marks that we often find in animal trails that don’t indicate dragging parts of a prey animal. In the next photo you see the trail of a long-tailed weasel bounding from bottom to top. There are grooves behind each landing spot, but they weren’t made by something being carried; the marks were made by the animal’s tail. Each time the weasel took off for the next bound its body sank into the snow, and the tail left a tapered groove. Tail marks are always connected to body impressions rather than being off to the side of the tracks as they are in the three preceding photos.

Here’s another example of potentially confusing disturbances that are not indicative of something being carried. The next photo shows the trail of a fisher walking from the lower right to the upper left. The fisher dragged the tips of its feet through the snow with each step. Notice that the drag marks are within the trail rather than to the side, and each drag mark extends completely or partially between two tracks.

Drag marks aren’t always as obvious as the ones shown above. In the next photo you see the trail of a coyote walking from top to bottom. In the lowest part of the photo there’s a thin line that was made by a single claw. There are wider gouges above that made by the rounded tips of the feet. But again the grooves lie within the trail width and always connect to tracks.

In the next photo we see what at first glance looks like the trail of some kind of otherworldly creature. It’s actually several coyote trails moving from left to right on a frozen waterway. To sort this out we need to focus in on the trail of each individual animal. The central part of the sequence draws our eye first: There’s an wavy drag mark that seems connected with the series of tracks in the center. If we look at just those tracks we see that they were made by a walking coyote. The drag mark seems to touch the prints, but toward the right it swings to the side and misses the tracks. This tells us that it’s not a foot drag but something that’s being carried. Above the central area there’s a similar string of tracks, and if we concentrate on those we see that they were made by another walking coyote. A third track sequence which lies below was made by yet another walking coyote. The outer trails are close to, but not on top of, the central trail, so there must have been two animals following close behind the one with the food item.

This scenario is supported by the next photo, which was taken in a place where the coyotes slowed down to go through a culvert. The tracks are closer together and the drag mark is more irregular. The drag mark touches one coyote print but misses the others, so it wasn’t made by the coyote’s feet. It’s definitely evidence of something being carried.

As to what was being carried, we can say it was a medium-sized object with a blunt projecting part and enough weight to make a deep groove in the snow. Claws would be thinner, an animal’s nose would be wider, an ear would be softer, and a tail would be fluffier and lighter. That would seem to eliminate all the medium-sized, winter-active animals in our region. But there’s another possibility: the detached body part of a deer with a protruding bone. The area where I found these tracks is a popular spot for hunters, and in mid-December, when I took the photos, coyotes would still have been scavenging on deer carcasses.

I’ll never know for sure, but a deer part is a reasonable conjecture, and conjecture is often what we’re left with when we attempt to understand the trail of a predators carrying dinner. Even without definite conclusions, the process of sorting out the details can be satisfying in itself.

The Marvels and Mysteries of Deer Tracks

When we think of deer tracks what usually comes to mind are heart-shaped prints like the one shown in the photo below. The paired toes together form the overall shape, and the pointed ends of the toes point forward. In tracks like the one in the photo, the ridge that runs front to back between the toes may be as important for identification as the toes themselves. In fact, the tell-tale ridge may still be visible even when most other track details have been destroyed by weathering or melting.

The specialized feet of deer are very different from those of their ancient five-toed ancestors. The two large toes that make up the print in the photo above are analogous to the third and fourth fingers of our hand, but the toe bones (analogous to our finger bones) are highly modified and are enclosed in tough, protective structures. There are two smaller toes, the dewclaws, which are analogous to our index and pinky fingers and sit higher up on the back of the leg. The innermost toe (analogous to our thumb) was completely lost in the course of evolution. You can see the arrangement of the large primary toes and the smaller dewclaws in the next photo of the front feet of a deer.

Photo from Deeryproof

Deer hooves are superbly adapted for running and jumping. Their keratinaceous outer sheathing combines with resilient internal tissues to cushion the feet against impact. The dewclaws don’t touch the ground most of the time, but with faster movement or on softer surfaces they can make contact to provide more support. In the next photo you see tracks made by a deer moving toward the right on a relatively soft substrate at a slow gallop. There’s a front print on the left and a hind print on the right. In each track the marks made by the dewclaws sit behind the impressions of the large main toes. (You’ll notice that the dewclaws of the front foot are angled to the sides while those of the rear foot are pointed more to the front.) The feet of deer are small relative to the animal’s size and bear more weight per unit area compared to non-hoofed mammals. This is why deer tracks show up on surfaces that are too firm to reveal the traces of most other animals (a serendipitous side-effect for trackers). It’s also why deer tracks are usually deeper than the tracks of animals like coyotes and bobcats, and why deer are generally less stealthy than mammalian predators.

You can see from the photo above that the two large toes are not always held tightly together the way they are in the first image. Sometimes a “four-toed” deer print can take on a bizarre appearance. In the next photo you see a hind track which has a resemblance to the bounding pattern of a squirrel. The tips of the large toes appear rounded because their points pushed downward under the soil surface.

Here’s an image of the front track of a rapidly accelerating deer in which only the marks of the dewclaws and the tips of the large toes registered.

Even when the dewclaws don’t touch the ground the two main toes may be separated, as in the photo below of a hind foot. Deer can exert muscular control over their toes and are able to spread them when they need more support or stability.

Here’s another shot of a rear track, again with the toes separated.

In the next photo you see some deer tracks I found on a seldom used railroad line. The animal had first walked through some mud and then travelled along the railroad track. It stepped carefully on the ties, and wherever it stepped it left muddy impressions. In the photo the direction of travel is from top to bottom, and what you see are the edges of the hooves printed in mud on the wooden ties. There are two tracks partly superimposed, the front print a little ahead of (below) the rear print.

If the tracks in the previous photo are hard to understand, the next image may help. There’s a front track (at the upper left) and a rear print (at the lower right), and the direction of travel is toward the upper left. The firm sandy base prevented the deer’s hooves from sinking in, and the thin covering of loose sand recorded the track details nicely. The outer rims of the hooves show as curved grooves in the sand, but the inner parts of the hooves barely touched the surface.

Tracks like these are sometimes misidentified as bird tracks, so beware! In fact it’s important to always be fully engaged–even with deer tracks–because, as the preceding photos show, they don’t always conform to our expectations. Every once in a while, among all the typical prints, you may find some that are surprising or puzzling. If you spend some time on these, you’ll gain a deeper understanding of deer tracks, both the common ones and the not so common ones.

What Goes In Comes Out

A big part of understanding animal lives is knowing what they eat. There’s lots of general information available in books and other publications, but to understand the dietary habits of the animals in one’s own landscape requires a few steps beyond that. We can observe animals when they’re hunting or feeding, and we can interpret chews, feeding sites, and feeding leftovers. But for many mammals, especially omnivores and carnivores, scat is the best tool. Scat contains the undigestible parts of everything an animal ingests, and it remains long after the creature has left the scene.

For herbivores, plant fibers make up the bulk of eliminations, so their scat has a grainy texture like the rabbit scat shown below. When herbivores eat foods high in water content their scat may be darker and softer, but the fibrous essence can still be seen.

Raccoons are omnivores, and their latrines often contain scats with a variety of contents. In the next photo you see raccoon scats with grape seeds and skins, apple seeds, ant parts, deer hairs, and the amorphous remains of deer flesh. An important safety note: raccoon scat may contain the eggs of a parasite that can infect humans, so it should never be touched with bare hands. To be on the safe side, it’s best to use sticks or other tools to manipulate scat, no matter whose it is.

The photo below shows river otter scat filled with crayfish shell fragments. In locations where fish are the main prey item, fish scales and bones will be the most common contents. In coastal marshes scats with crab shell fragments may predominate, indicating that crabs make up the bulk of the animals’ diet.

For many omnivores and carnivores scat contents vary with the changing seasons. The bear scat shown below was photographed in early May, and it’s made up of the remains of the newly emerging leaves and shoots the bear had been eating. Bears lose weight during hibernation and for many weeks afterwards because the grasses, sedges, and young shoots they must subsist on are energy-poor foods.

It’s only when higher quality edibles become abundant that bears begin to put on the pounds. The bear that left the scat shown in the next illustration had been feasting on black cherries. The summer diet of fruits and berries is often supplemented with insects, and you may find bear scats containing ant or yellowjacket parts.

Scats like that pictured below, full of fragments of acorns and hickory nuts, begin to show up in late summer. The seasonal abundance of acorns, nuts, and fruits, as well as increasing insect populations, provides a crucial, energy dense diet. At this time bears transition into a period of hyperphagia, and spend most of their waking hours seeking food or eating. The fat stores they put on will carry them through their winter hibernation.

The scat of canids reveals that their diets also follow seasonal cycles. Winter and early spring fare is mostly made up of animal prey and carrion. Signs of feeding on deer carcasses start to show up during the fall hunting season and continue through the winter. The coyote scat in the photo below contains deer hair and leg bone fragments. Foxes also feed on deer carcasses, but they aren’t powerful enough to crack large bones to get at the marrow the way coyotes do. Deer killed by hunters (and the carcasses resulting from the vehicle collisions that seem to spike during hunting season) may be preserved well enough in the cold to last through most of the winter. Carcasses of winter-killed deer also provide scavenging opportunities.

The red fox scat shown below (photographed in mid-March) contains the remains of a small rodent that was swallowed whole. There’s a leg bone in the chunk at the lower left, a molar in the piece at the top, and an incisor in the segment at the lower right. The bones are embedded in twisted masses of short hairs. Positioning its scat on the manhole cover was the fox’s way of signaling its presence to other foxes in the area. Small rodents and other small mammals are a winter mainstay for foxes and coyotes.

Like bears, canines graduate to summer foods as they become available. A sure sign that berries are in season are finds like the coyote scat shown below, filled with raspberry seeds. Note that the segments are tubular and blunt-ended rather than tapered like scats made up of animal remains.

As summer progresses, the menu widens. The red fox scat in the next photo (found in early September) contains acorn shells, apple skins, and fragments of field corn kernels.

Some scats lead to surprising discoveries. The next photo shows some gray fox scat containing the remains of a frog. Hollow leg bones are clearly visible, and when I pulled it apart I saw the still articulated bones of a rear foot. It’s a bit unusual to find frog remains in fox scat, but the really surprising thing is that I found this in early December. The weather had been mild, and apparently some frogs had not yet gone underground for the winter.

Food is central to survival, and scat can provide direct information about what animals eat and when they eat it. The many stories scat has to tell can illuminate not just feeding habits, but also interactions among animals, and interactions with the surrounding landscape. Each story adds to our connection with the animals around us.

Gray Fox Affairs

It’s been a strange winter. In my neck of the woods we had some significant snow early in the season, but no big storms since then. Temperatures have been up and down (more up than down), and with all the melting, the snow we do have has consolidated into a dense, icy layer. Much of the time the conditions have been terrible for tracking, but every once in a while something wonderful has happened: warmth and liquid precipitation have been followed by dropping temperatures and a change from rain to snow. When this happens, snow that falls while the air is still relatively warm becomes bonded to the crust. As the temperature drops and additional snow falls, it forms a soft layer on top. The result is a non-slip and easily navigable surface that is a perfect medium for recording tracks.

A few days ago I encountered just such conditions: an icy base covered by a thin layer of soft snow. I was in an extensive natural area, and both the forest road I was following and the surrounding landscape offered beautiful tracking conditions. Animals of all sorts had been moving easily over the snow, and there were tracks everywhere. I found myself following the trail of a gray fox. The animal went for quite a distance at an easy trot, but then it did something that was quite puzzling.

The photo below shows the fox trail as it goes from upper left to lower right. (You can also see a coyote trail to the right of the fox trail, and a mountain bike trail to the right of that.) As it entered the frame the fox was walking (the first three tracks at the upper left). In the next section (between the last walking step and the edge of the tree shadow) the pattern was very different, and following that the trail looks unlike either of the previous sections. I wanted to know what was going on and why the middle section looked so different.

In a situation like this the first thing to do is identify each track. The zig-zag of the walking section helps us to tell right and left, and the fact that the front foot is larger than the hind foot distinguishes front from rear. The next photo shows a gray fox front print on the left and a gray fox rear print on the right. You can see the difference in overall size and also the difference in the sizes of the middle pads.

The photo below shows just the puzzling middle section, and if you compare photos you’ll see that the front and rear in the photo above are actually the first two tracks in the middle section. It’s pretty clear that the first four prints in the photo below are left front, left rear, right front, right rear. After that it gets harder. The track just above the right rear is smaller than the one to its right, so those two prints must be left hind, left front. Three tracks from the right side come next, and it looks to me like the sequence is right rear, right front, right rear. The final two before the tree shadow are the left front and the left rear, and at the edge of the tree shadow there’s a right front with a right rear partially superimposed on it.

In the next photo I’ve added labels showing my take on right/left and front/rear. If we start at the beginning of the whole sequence, the animal was trotting (those tracks aren’t seen in the photos) and then slowed down to a walk (the first three tracks in the distance shot). The next section shows that the fox slowed even more to an overstep walk (the first four prints in the photo below), then slowed even more to an understep walk. There’s an extra right hind that’s puzzling, but I’m guessing the fox just repositioned its right hind foot. Then the overstep walk reappears after which the fox picked up the trot (the two impressions at the lower right in the first photo). Notice that the step lengths in the overstep part are shorter than the regular walk steps that preceeded them, and the step lengths in the understep part are shorter yet.

That analysis was rather involved, but it leads to a picture of what the fox actually did. As it trotted along something it detected made it slow down, first to a walk and then almost but not quite to a standstill. It was probably sniffing and listening intently as it moved very slowly. Once the animal concluded that it was okay to move on, it resumed its journey at a trot. It’s impossible, without more evidence, to know what caused the fox to react the way it did. It may have been a threat, but it could also have been something that interested it for a different reason. It is, after all, mating season for wild canines.

And the fox I was following was definitely tuned in to mating season. Farther on I found a spot (shown in the next photo) where the animal had detoured to urinate on a small spruce branch. If you look in the center of the frame you’ll see a squiggle of urine that runs horizontally from the upper edge of the spruce branch. Because the urine wasn’t squirted out the side of the tracks we know this was a female. She would have lifter one hind leg forward and supported herself on the other hind leg (plus two front legs) as she urinated. The relative depths of the tracks tell us that the supporting rear foot was the left. Its track is in the prominent double impression above and to the left of the urine.

I’ll never know what made the gray fox slow down and leave the pattern discussed in the beginning of this article. It could have been a threat–there was certainly a coyote in the neighborhood, or it could have been the mountain biker. A fisher (whose tracks I also found on that day) would have made the gray fox nervous. And there were red fox trails as well. But the trail shown in the photos above doesn’t suggest alarm so much as cautious interest. The fox didn’t change direction but just continued on. Was it another gray fox, one she was familiar with, or one she had mated with in a previous year? We have a small part of the whole story, and we can only speculate about the rest, but it’s fascinating just as it is.

Where Do The Bones Go?

Have you ever wondered what happens to all the bones? Animals are dying all the time, and when they die their soft tissues are eaten by predators and scavengers, picked off by birds, ingested by insects, and decomposed by microorganisms. This leaves just bones, like those of a rabbit shown below. But we don’t see bones littering the landscape, so what happens to them?

First let’s consider small animals. When a tiny creature such as a vole is killed by a predator, the catch is swallowed whole and the bones are crushed and partly assimilated. Undigested bone fragments are eliminated in scat (or pellets if the hunter was a hawk or owl). You can see small bone fragments in the red fox scat shown below–there’s also plant material, tiny hairs, and what appears to be a whisker. Scat like this will eventually be weathered and dispersed into the soil. Even if a small animal isn’t completely consumed immediately, its remains will be broken down, dispersed, and probably hidden from our view by its surroundings.

But what of larger animals whose carcasses would be more obvious? Deer immediately come to mind, but the question also applies to bears, coyotes, woodchucks, raccoons, and other similar sized animals. We do occasionally see the remains of recently deceased animals, like the deer carcass in the next photo, but why don’t we see piles of old bones lying around everywhere?

The answer has to do with the nutritional value of bones. The deer femur in the next photo was cracked open by a coyote to get at the marrow. (I say coyote because the only other animal in our region which is powerful enough to break a deer leg bone would be a bear, and there were no bears in the area where the bone was found.) Toward the upper end of the larger piece you can see some striations which were probably made by the coyote’s molars as it worked at the bone.

We sometimes see evidence of the utilization of bones this way in scat. The coyote scat in the next image contains an abundance of deer bone fragments and deer hair. The hair would have cushioned the sharp bone edges and prevented injury to the animal’s digestive system. It wouldn’t take long for bone fragments like these to be hidden in the upper layers of soil.

In addition to marrow, bones contain calcium, phosphorus, and other minerals which may be lacking in the diets of wild animals. Mineral deficiencies are especially likely for herbivores. Many animals supplement their nutrient intake by chewing on bones, and they usually choose less daunting ones such as scapulas, ribs, and vertebrae. The bones of birds, reptiles, and smaller mammals such as rabbits can also be utilized by less powerful animals. Even deer have been observed chewing on bones. This kind of chewing may not leave obvious signs–just ragged edges, missing ends, or random gouges.

Rodents also gnaw on bones, and the evidence of their activity is often more conspicuous. In the next photo you see a segment of deer leg bone lodged on a midden at the base of a Norway spruce tree. Middens, piles of discarded cone cores and scales, are created when a red squirrel repeatedly uses a favorite perch to feed on cones. The red squirrel that claimed this tree must have used the same perch to work on the bone.

In the next photo you can see the grooves made by a squirrel’s incisors as it chiseled off bone shavings.

Smaller rodents, like voles and white-footed mice, leave finer grooves like the ones in the next photo.

These creatures weren’t after marrow, since the bones were relatively old and the marrow had been removed long ago. This behavior is probably driven in part by the need to supplement their mineral intake, but rodents also chew on bones (and antlers as well) to maintain their teeth in good condition. Their incisors grow constantly, and are subject to malocclusion if not shaped and worn down with regular gnawing. The same is true for rabbits and hares, which are also known to gnaw on bones.

As time passes carcasses are pulled apart and bones are cleaned of soft tissue, scattered, broken, crushed, pulverized, chewed, and ingested by many different animals. Rather than piling up as useless cast-offs, animal bones gradually disappear as they are utilized by living creatures. Animals are part of the web of life both while they are alive and after they are dead.

Conspicuous Communication

If you’ve ever found a pile of feces perched in a conspicuous spot, you’ve encountered a message from an animal. Canines are especially likely to communicate this way, and they’ll use any location that makes a good exhibit. The photo below shows red fox scat displayed on the base of a fallen log. There’s both recent and older scat–recognizable by its lighter color–indicating that this location has been used more than once. One older chunk is nestled in the center of the new deposit and another rests below it on a shelf of wood.

Our olfactory abilities are too limited to appreciate the complex bouquet of chemicals in scat, but for canines–and probably other species–each deposit conveys information. The specific content of the communication could be establishment of a territorial boundary, advertisement of mating availability, or reinforcement of group cohesion. Scat can also indicate the health, status, and identity of the animal which produced it. The coyote scat in the next photo was in the center of a road rather than on a raised object, but it’s placement made it noticeable nevertheless. I found this in June, when we would expect coyote parents to be leading their offspring on short explorations, and my best guess is that the message was territorial in nature.

Important locations may accumulate a number of deposits. The rock in the next image must have been significant, because there are four different scats on the rock and several more which fell off to one side and aren’t visible in the photo. All of the deposits were left by red or gray foxes, and the contents include apple skins and seeds, hair and small bones, and insect parts. The most intriguing one is the chunk at the lower right.

A closer look shows that it contains porcupine quills.

An ant mound formed the pedestal for the red fox scat in the next shot. I found it in early spring, so the ants would still have been deep underground when the animal stood on the mound and dropped its feces directly on top.

Manhole covers can provide suitable display locations. The red fox that left the scat in the next photo had dined on a small rodent, as indicated by the short hairs and small bones it contained. The manhole cover was in a grassy trail and allowed the scat to stand out in the uniformly green surroundings.

Sometimes scat seems to represent an assertion of confidence. Coyotes will kill foxes, so the smaller canines are usually careful to avoid encounters. In the photo below a recent gray fox scat (at the lower right) sits on an older accumulation of coyote scat. The deer hair in the coyote scat shows that the animal had scavenged on a mostly cleaned out carcass, while the gray fox had eaten meat from a fresher carcass.

Any protruding object is a potential platform for canine scat. The photo below shows a deposit of coyote scat on a pile of horse dung.

In the next photo you see one of my most surprising finds. A gray fox had deposited scat on top of a rock cairn which marked a trail junction. This must have required a delicate balancing act, because the pile of rocks was tall enough that the fox would have needed to place at least one rear foot on the cairn.

The conspicuous locations often chosen by wild canines mean that we often notice the scat left by wild canines. We’re less adept at interpreting the messages contained therein. But even if we miss what’s most important to the animals, it’s fun to enjoy the creative and sometimes whimsical positioning of the scat of foxes and coyotes.

Knowing Coyote Tracks

Coyotes are one of our more common predators, but when we find a possible coyote track it can be difficult to identify it with certainty. Could it be a fox? Or maybe a bobcat? And there’s also the possibility of domestic dog. Dog tracks show up almost everywhere and are often mistaken for coyote. In this post I’ll share some thoughts on how to separate coyote prints from some confusing look-alike tracks.

First let’s deal with felines. The bobcat track below is a right front print, oriented toward the top of the frame. Like coyotes, bobcats have four toes and an undivided middle pad, but unlike coyotes (and other canines) bobcat tracks are asymmetrical. They have a leading toe (the second from the left in the photo) and a trailing toe (the right-most one), and the middle pad is canted to the outside. Try this simple test for symmetry: Imagine a vertical line which passes through the center of the track, and then imagine folding the right half of the track over onto the left half. You’ll see that they don’t match up. Now do the same thing with the track in the next photo, a coyote front print, again oriented toward the top of the photo. You’ll see that the right half matches almost perfectly when folded onto the left half.

Bobcat right front track

Coyote right front track

Both the bobcat and the coyote prints pictured are clear and complete, but because of varying conditions some bobcat tracks–especially rear prints–appear more symmetrical, and canine tracks sometimes have an asymmetrical look. Fortunately, there are other features that can help to distinguish the two. An important feature is the shape of the ridges between the toes and the middle pad. In the coyote track the large ridges between the toes and the middle pad form an X, and at the central point of the X there’s a dome. The major ridges in the bobcat track don’t form an X–they could be described as a squashed H or a partly rotated C-shape with some kinks. Another characteristic to look at is the relative sizes of toes and pads. In bobcat tracks the toes are small in relation to the overall track size, and the middle pad is large. In coyote tracks it’s the reverse: the toes are larger and the middle pad is smaller in relation to the overall track size. In the coyote track there are some delicate claw marks, two close together ahead of the leading toes and a lighter one on the left outer toe. Claw marks are absent in the bobcat photo. If more grip is needed a cat may extend its claws, but claw impressions are much less common in bobcat tracks than they are in coyote (or other canine) tracks. Bobcat prints also tend to be rounder, and coyote prints are more oval or egg-shaped.

Then there’s red fox, whose tracks overlap with coyote tracks at the lower end of the coyote size range. The next photo shows a red fox front print, oriented toward the right side. It’s similar to the coyote track in being symmetrical, and in having the canine X and dome, but there are some features that separate it from coyote. The hair that covers the underside of the fox’s foot shows as striations in the toes and middle pad. This hair gets worn down as the season progresses so it may be less conspicuous in late summer and fall, but in early winter a new growth of thick hair develops. Red fox tracks in snow often have a blurry appearance because of the dense hair. The undersides of coyote toes and middle pads are bare of hair in all seasons, so the toe and pad impressions have smooth surfaces and crisp outlines.

Red fox left front track

In the middle pad of the red fox print there’s a curved indentation (vertically oriented in the photo) made by a ridge of tough skin that protrudes through the hair. This bar or chevron (present in the front foot and very rarely in the rear foot) is unique to the red fox and, when visible, separates it conclusively from the coyote. In the preceding photo of the coyote track you can see that the bar is absent.

Distinguishing coyotes from domestic dogs can be the toughest challenge. Dogs are so variable that there aren’t any absolute criteria, and many dog tracks are similar to coyote tracks in size. The photo below shows the rear (on the left) and front (on the right) prints of a coyote, oriented toward the right. As in most canines the rear track is smaller than the front. Note the absence of claw marks except for the delicate, closely set pricks ahead of the leading toes of the front foot. Both front and hind tracks are oval in overall outline, and their middle pads are small in relation to the overall track size.

Coyote rear (left) and front (right) tracks

Comparing those tracks with the dog tracks in the next photo, we see some clear differences. The front track of the dog (above) is more rounded and has a larger middle pad. The claw marks in the front print are more robust and are present ahead of all four toes. The rear print of the dog (below) is slimmer than the front but has a conspicuous middle pad, and there are claw marks ahead of all four toes.

Domestic dog front (above) and rear (below) tracks

Dog tracks like the front print below (oriented toward the top) are even easier to identify. The large middle pad and the thick claw marks are strong indicators, but the most striking feature is the spreading of the inner and outer toes. Many dogs have “floppy” feet. Because they are not as active their feet lack the muscle tone of wild canines, and their toes spread more. The inner and outer toes and claws may point to the sides rather than straight ahead. Dogs that get plenty of exercise, like the one that made the tracks in the preceding photo, may not show this spreading.

Dog front track

Varying conditions can affect the appearance of coyote tracks, and this is where things can get confusing. The coyote front track (facing to the right) in the next photo doesn’t look as neat and tight as the coyote tracks shown in previous photos. There are claw marks ahead of all four toes, the inner and outer toes aren’t as tightly tucked in behind the leading toes, and the claw marks are more divergent. This animal was trotting on soft, moist sand, so it allowed its toes to spread slightly for support. But the track still shows the small middle pad and the delicate claw marks that point toward coyote rather than dog.

Coyote front track from side trot

Faster movement can have an even greater effect on tracks. The print shown below (a front, pointing toward the right) was made by a galloping coyote. The toes are spread, the claw marks are deep, and the middle pad looks asymmetrical. But even this track shows coyote rather than dog features. The claws are sharply pointed and the middle pad is small compared to the overall track size.

Coyote front track from gallop

There will always be times when making a firm identification is difficult. The tracks may be distorted or degraded, or there may only be partial tracks. But even if we can only come to a tentative conclusion, we can still observe and learn as much as possible. And the more we struggle with challenging situations, the better we will be at knowing coyote tracks when we see them.

Canine Romance

It may seem like the wild creatures are all hunkered down, just doing their best to stay alive and wait out the cold season. But for wild canines there’s more going on than simple survival. This is mating season for foxes and coyotes, and they’re engaging in behaviors that will eventually lead to reproduction. For human trackers the first clue to their new fixation is the increasing frequency of scent marking. In the photo below you see a splash of urine on the snow to the right of the corn stalk, left as a message to others of its kind by a gray fox.

Urine contains complicated combinations of chemicals that, to a discerning canid, reveal the identity and health status of the animal that produced it. As mating season progresses, changes in the chemical signature also indicate the animal’s readiness for mating and reproduction. Most of these messages are too subtle to be detected by people, but fox urine is an exception. The urine of both red and gray foxes takes on an increasingly musky, skunk-like odor as hormonal changes progress, and in late winter this odor is strong enough for a person to detect it a good distance away from the deposit.

The fox whose scent mark is seen in the image above was walking from the upper left to the lower right. We know that the it was a male because of the placement of the urine off to the side of the animal’s trail. The direction of travel is revealed by the appearance of the snow around the edges of the tracks. When a foot goes down into snow it pushes any movable material down into the hole. When the foot comes up and out again it often brings a little snow up with it, and this snow is dropped around the leading edge of the track as the foot moves forward above the surface. This means that the snow around the entry end of a track is relatively undisturbed while the surface at the exit end is decorated with sprays or scatterings of snow. In the photo of the gray fox trail there are four deep tracks, each one the landing place of a front and a rear from the same side, plus a light track near the third deep track. Starting at the upper left (and considering just the deep tracks), the sequence is left front + rear, right front + rear, left front + rear, right front + rear. The animal was standing on its right hind foot when it lifted its left hind leg to squirt urine at the corn stalk. The shallow print was probably made as the fox placed its right front foot lightly on the snow for balance while it was urinating. The corn stalk was a convenient object, but rocks, clumps of weeds, branches, or anything else that protruded above the snow would have done as well.

Among coyotes and foxes, early winter is the time for the establishment or reestablishment of pair bonds. Those that spent time apart after they raised a litter in the previous season usually rejoin, and unattached animals roam widely in search of potential mates. Bonded pairs establish their territory by scent marking around the edges, especially along borders shared with others of their species. Unless we are familiar with the area and the animals involved it’s hard to know whether scent marks are advertisements of availability or warnings that the territory is occupied.

During the lead-up to mating, pairs often travel together. The trails in the photo below were made by two red foxes travelling along a forest road. For at least half a mile the two trails wove back and forth, occasionally changing speed and sometimes diverging, but always coming back together. The male, with slightly larger tracks, enters the frame at a gallop, moving from the lower left to the upper right. The female is doing a side trot and her trail comes in at the lower right and leaves at the top of the frame just to the left of the male’s trail.

All of the behaviors I’ve described above help to strengthen the pair bond and propel the hormonal changes that lead up to mating. When the female’s endometrial lining begins to develop, her urine contains blood, and she leaves scent marks like the one in the photo below. She’ll soon go into heat and only then will she be receptive to the male’s advances.

The pair are both involved in the process of den selection and preparation, and pups are born about 50 (foxes) or 60 days (coyotes) after successful coupling. By initiating the early stages in the dead of winter nature insures that the pups are born in the spring when food will become increasingly abundant. Note: It’s important for trackers to avoid disturbing animals during this vulnerable time. We should not approach too closely or otherwise disturb a den site starting with the period of den preparation and continuing until the pups are no longer dependent on the den for safety.

This is, by the way, why coyote-dog hybrids aren’t as numerous as some people believe. Over thousands of years of domestication, dogs have lost the finely tuned sequence of reproductive behaviors that occurs in wild canines. Mating in dogs is no longer synchronized with the seasons, and males don’t assist in the raising of pups. Since these behaviors are genetically controlled, the offspring of matings between dogs and coyotes have disrupted patterns of behavior. The precise timing of reproduction is lost, as well as the strong pair-bonding and the dual effort from both parents (and sometimes female offspring from the previous year). For this reason the offspring of matings involving dog-coyote hybrids are unlikely to survive.

This is a great time of year to let tracking open a window into some of the underlying processes of the natural world. The mating rituals of wild canines have been shaped for success by natural selection, and this is beautifully illustrated in the behaviors we see in the tracks and trails of foxes and coyote.

When Trails Cross

Was the fox afraid of the fisher? Did the coyote chase the rabbit? Questions like these often come up when we find animal trails that intersect. And as always, the tracks tell the story. In the photo below a coyote trotted along a forest road, the direction of travel from upper left to lower right. A rabbit bounded across the road, leaving a trail heading from right to left. Both trails had been made early on a cold morning, and I came upon them not long afterwards. Neither trail showed any changes in pattern or speed in the vicinity of the intersection (although the rabbit took a few slow hops as it entered the road). The tracks in the photo tell us that whichever animal came second, it wasn’t alarmed or excited by the trail it was crossing.

Here’s another example: A coyote had trotted from upper right to lower left, and at least a day later a fisher loped from lower right to upper left across the coyote’s trail. The unchanging pattern of the fisher trail tells us that it had no apparent reaction to the older coyote trail.

In the next photo you see another instance of a fisher crossing a coyote trail. The coyote was trotting towards the upper right, and the fisher loped from right to left. But this time the tracks near the intersection reveal a definite reaction on the part of the fisher. The change in rhythm and the extra tracks tell us that the fisher was very interested in the coyote trail.

Parsing out all those extra tracks is tricky, but you can see my interpretation of the encounter in the next photo, a close-up in which I’ve labelled the tracks. The coyote trail is a nearly straight sequence of tracks on a rough diagonal from lower left to upper right, and its tracks are marked as CL F+H, CR F+H, etc. The fisher tracks are labelled RH, LH etc. Starting at the lower right there’s a right rear track from the fisher’s loping approach, and to the left of that track there’s a group of five prints. Four of those tracks make up a shortened lope pattern and the fifth sits above them and points toward the eventual continuation of the fisher’s journey. The tracks closest to the coyote trail show how the fisher paused and did a thorough examination. Apparently satisfied with its inspection, the fisher continued loping in the original direction.

Why was the fisher so interested in the coyote trail? A coyote would represent a danger to a fisher. A fight between the two could cause the fisher’s death and also pose needless risk for the coyote. But encounters between predators rarely happen because they keep tabs on each other’s movements. The tracks would have revealed the identity and nearness of the coyote, and the fisher apparently decided that it wasn’t in any danger.

I found the coyote tracks in the next photo on a sunny morning following an overnight snowfall. I must have been there not long after the coyote came through, since its tracks didn’t show any signs of melting. The coyote walked from right to left, changing its direction as it crossed an otter trail (which also showed no signs of melting) but otherwise taking little notice of the mustelid’s slide.

I continued to follow the coyote trail and soon came upon a spot (shown in the next photo) where the animal had encountered several pheasant trails. The pheasants had been there earlier in the morning before the sun had risen above the distant trees. The snow would have been several inches deeper, and the pheasants would have dragged their feet through it. Once the sun rose higher it began to melt the snow. By the time I came along the depth of the snow had been reduced and the pheasant tracks had been transformed into a series of pits connected by a raised, wavy ridge. How did this happen? Disturbances created by footfalls create slightly denser snow around–and between, if the feet drag–tracks, and denser snow melts more slowly than undisturbed snow. The compacted snow around and between the pheasant prints sank down more slowly and was transformed into the raised ridge. The coyote came along shortly before my passage, so its tracks hadn’t been exposed to the sun for very long and were unaltered. As the coyote investigated the pheasant tracks it left a jumble of prints, but it probably decided the birds were already far away and not worth pursuing.

So why did the coyote react differently to the two trails it crossed? The otter trail was more recent, judging by the lack of alteration, but a powerful animal like an otter would not have been seen as potential prey by a coyote. A pheasant, on the other hand, would provide a welcome meal for a hungry predator.

Signs of interaction when creatures cross paths may not be as obvious as the examples I’ve described above. You might just see a lighter track a little to the side, made as an animal paused before continuing on. Or differences in speed or gait may reveal an awareness of the recent presence of another creature. Whatever the reaction, it will always be transmitted through the animal’s feet and written in its tracks. Reading those tracks opens a window into the life of that animal.