animal signs – Page 2 – Linda J. Spielman

Deer Browse

Signs of spring are all around us, but there are still some interesting discoveries to be made about the past season. Early spring is a perfect time to learn about the winter diet of white-tailed deer. We may think that deer are basically grazers as we see them placidly feeding in fields, like cows and horses. But that would be wrong. Cows, horses–and bison, to include an example of a wild species–are strict grazers and consume grasses, forbs, and other non-woody plants year-round. Deer are browsers rather than grazers. Although they feed on the same kinds of low-growing vegetation as grazers during the growing season, in winter they switch to the twigs, buds, and bark of woody plants. The deer you see in the lead photo (not my shot, but I couldn’t find a good attribution for it) are eating the twigs of a cedar sapling.

Deer do not have upper incisors, so in order to remove a twig they clamp it between their lower incisors and their tough upper palate. A jerk of the head suffices to yank the twig off, enabling it to be macerated by the molars and then swallowed. Rough breaks like those shown on apple in the photo below indicate that deer were feeding on the small twigs.

This contrasts with the sign left by rabbits and hares, which also depend on woody browse for winter food. Rabbits have both upper and lower incisors, and they make sharp, angled cuts like the ones shown in the next photo of multiflora rose.

The browsing preferences of deer vary in different regions. Some of their favorites in the northeast are sugar maple, ash, dogwood, striped maple, northern white cedar, and hemlock. In the next photo you see a sugar maple branch that was browsed by deer. The animals are not equipped to chew on larger branches, so they limit their browsing to the small twigs and buds at the branch tips. In mature forests these only become available if trees or large branches fall, which is exactly what happened in this case.

Hungry deer will eat everything they can reach, and unrelenting feeding often leaves browse lines like the one on northern white cedar in the photo below. This doesn’t affect the overall health of the stand, but browsing can have adverse effects on the growth of smaller trees.

The ash seedlings in the next photo show the excessive lateral branching patterns that result from heavy browsing. During each growing season the young trees form new twigs and buds, but each winter the new growth is eaten by hungry deer. The stunted trees are never able to outgrow the reach of the deer and eventually die.

Deer found a hemlock sapling at the edge of a field, and you see the result in the next photo. It’s hard to see the hemlock against the background because so many of the small twigs have been eaten, but if you follow the main stem up from the bottom center of the photo you’ll see how much foliage is missing.

Overbrowsing makes a difference in the appearance of forests. In the next photo you see a woodland that has been heavily impacted by winter deer feeding. The lack of understory trees makes it easier to walk through this kind of forest, and its cleaner appearance may be more appealing. But this forest is in trouble.

In the next photo you see a much healthier woodland. The spaces between the large trees are filled with young and medium-sized saplings, and these are the ones that are ready to fill gaps when larger trees die or fall.

Without a multi-aged understory, forests have limited ability to regenerate. When large trees die, there are no young trees ready to fill in the gaps. It’s true that there are seeds in the soil that will germinate quickly once openings are formed, but the delay in regrowth may allow invasive species to get a foothold. Signs of deer browsing tell us much more than the mere presence of hungry animals. There are larger lessons to be learned, and nature is ready to share them if we are willing to pay attention.

Squirrel Marking

Some animal communication is just for the moment, gone as soon as it is created, and some is more permanent. Whether it’s a patch of earth pawed by a deer, a scat deposit carefully positioned by a fox, or a twist of grass left by an otter, messages left in physical media can convey information long after the author has left the area. Squirrels are especially adept at this type of messaging, and their medium of choice is something they are intimately acquainted with–wood. Tree trunks, branches, roots–all can serve as bulletin boards for intra-species communication. One of the best times to observe squirrel marks is early spring, after the snow is gone but before new leaves limit our view through the forest.

The photo below shows an opening into the trunk of a large red maple. Hollow trees provide critical winter shelter, and this one must have been prime real estate because the hole has been bitten around the edges by a squirrel. Gray, red, and flying squirrels (of both sexes) use their incisors to declare ownership of desirable nesting spaces. Theoretically the sizes of the gouges should tell us which species did the marking, but the hole was about thirty feet up, and it’s hard to measure tiny things like tooth marks when you’re that far away.

The creature claiming possession of the tree in the next photo is easier to determine. Gray squirrels, primarily males, make vertical marks called stripes to assert territorial claims. They seem to prefer rough-barked trees like the white oak pictured in the photo, and the stripes are generally found on large trunks between 2 and 6 feet above the ground. I’ve also seen gray squirrel stripes on red oaks, chestnut oaks, hickories, and tulip trees. After marking, a squirrel may rub its cheek on the bitten area to leave its scent. You can see from the varying degrees of weathering that this tree has been marked repeatedly over several years.

Red squirrels also have distinctive ways of creating messages, and one of the easiest to find is the branch marking associated with conifer middens. Middens are accumulations of discarded cone scales and cores found below habitual feeding perches. The photo below shows a midden at the base of a Norway spruce. Most conifers, with the exception of some pines, tend to retain lower branches for years after they have died, and these provide perfect feeding perches. The oversized cones (up to 8 inches long) produced by Norway spruces are prized by red squirrels, and the middens came become quite large.

If you examine the branches above a midden you’ll probably find bite marks like the ones shown in the next photo. The image shows a Norway spruce branch which extends horizontally about four feet up the trunk. The upper surface of the branch is adorned by numerous bite marks. You can see the midden (out of focus) on the ground below the branch.

Red squirrels also make marks at or near ground level. In the photo below you see a Norway spruce root which has crossed over and been lifted over the years by the swelling root crown of a neighboring tree. This tree was part of a plantation that dated from the 1960s, and the trees were close enough together that horizontally spreading roots often passed close to the bases of neighboring trees. This also happens in other conifers when they grow in crowded stands, and the small lateral roots have thinner bark than the trunk and the larger roots.

A closer look, shown in the next photo, shows that a red squirrel has bitten through the bark of the lateral root. The light colored gouges are recent marks and the whitish ones are older, probably made the previous year and covered with dried resin.

Norway spruce plantations were established throughout the east during the Depression and also later in the 20th century. With their large crops of oversized cones, stands of Norway spruce are preferred habitats for red squirrels and are great places to investigate red squirrel marking. Other conifers were also used for reforestation projects, and if they support resident red squirrels you’ll probably find evidence in the form of marking and middens. Both branch marking and root marking are the animals’ way of defending their underground larders of winter food.

Squirrels also use their incisors for purposes other than marking, such as debarking trees to get at the living cells of the cambium. The photo below shows a staghorn sumac that was fed on by a gray squirrel. I found this a few years ago in early March, and the color of the exposed wood indicated that it had been done not long before. Late winter and early spring can be a time of scarcity; stored food supplies may be exhausted and squirrels may be forced to turn to foods which are less nutritious or harder to access. I’ve occasionally found similar cambium feeding by squirrels on sugar maples.

Squirrels, both red and gray, also tap trees when the sap flows in spring. The animals choose vigorous trees, and bites are made in living, thin-barked branches by anchoring the upper incisors and drawing up the lower ones. This creates what Sue Morse calls a d0t-dash pattern. Two fresh bites on a sugar maple branch are shown below, and above them there’s an older bite. Interestingly, the sap is not consumed immediately, but is allowed to dry. Once the water has evaporated the squirrel returns to lick up the crystallized sugar.

When we find a mark made by a squirrel, we can infer something about the availability of food or the presence of a desirable nesting site, but for other squirrels there’s much more involved. The associated cheek rub or saliva deposit is unique to the individual and carries information about its sex, health status, and possibly other characteristics. Even though receiving these messages is beyond our abilities, I enjoy finding squirrel marks and imagining the messages they convey to their neighbors.

Mouse Maneuvers

The mouse–not most people’s favorite creature, to put it mildly. Certainly the house mouse can be a serious pest, but wild mice are different creatures altogether. To start with, they are more attractive than the drab house mouse, as you can see from the portrait of a white-footed mouse which heads this post. The white-footed mouse is one of two species which inhabit the northeast, the other being the deer mouse. They are closely related (both belong in the genus Peromyscus) and are so similar they can’t be distinguished from tracks or sign. Habitat may indicate which one we’re dealing with, but from the tracker’s perspective it’s not really important, since they have similar characteristics and behaviors. White-footed mice prefer deciduous and mixed forests at low and moderate elevations. The trails shown below were most likely made by deer mice, which are more common in boreal and high elevation forests.

Both deer and white-footed mice are hunted by just about every predator in our region, so they stay hidden whenever they can. In warm months they find safety within woody debris, shrubs, blowdowns, rocks, log piles, and sometimes human structures. In winter, snow usually provides ample cover. Mice are able to tunnel through snow if it’s not too dense, and deep snow actually contributes to their survival. Within a deep snowpack the temperature is highest at ground level and decreases toward the surface. The temperature gradient causes ice crystals in the lower levels to sublimate and recrystallize at higher levels, leaving spaces where small animals can find safety and warmth. Hollows at tree bases, among rock outcrops, and under downed logs and branches allow mice to move between the surface and the lower regions (the subnivean zone). That’s why the trails in the photo above radiate from the base of the tree at the upper edge of the photo.

The next photo shows a steep, snow-covered embankment at the edge of a groomed snowmobile trail. A mouse (it could have been either a white-footed or a deer mouse) bounded from the lower left across the packed snowmobile trail toward the slope. The mouse turned to the right and then went under a slight overhang where it found (or dug) a tunnel leading to safety in the deeper snow bordering the snowmobile trail.

Look under the log in the next photo and you’ll see mouse trails. Notice how the mouse trails run into (or out of–or both) the cavity at the upper left, a mouse-sized hole at the lower right, and unseen openings under the lower part of the log. As long as these openings are maintained, mice can move easily between the snow surface and the subnivean realm. The log also provides protection from aerial predators.

In soft snow mouse trails on the surface often lead to holes that connect to tunnels deeper in the snow.

Both deer and white-footed mice store nuts and seeds in cavities in logs, standing trees, and rock piles. Once winter comes any space protected by deep snow makes a good feeding area. The midden of black cherry seeds in the next photo shows where a mouse fed beneath the snowpack at the base of a tree. The neat round holes are reliable indicators of mouse feeding.

Mice use logs as travel routes, but we only see evidence of this when a light covering of snow coats the log surfaces. In the photo below you see a jumble of mouse tracks, a few of which show toes clearly enough to reveal the direction of travel. There’s a rear print at the lower left that points toward the left, and you can see a few front tracks near the upper edge of the snow with toes pointing toward the right.

There are other small mammals, voles and shrews in particular, whose trails can be confusingly similar to those of deer and white-footed mice, especially when they are bounding. But the bounds of voles and shrews are less regular and have more variable foot placement than the bounds of mice. Voles and shrews also use a greater variety of gaits than mice, including walks, trots, bounds, and lopes. Voles especially are likely to make frequent gait transitions, and often use a perplexing gait sometimes described as a shuffle. Mice can walk but it’s rare, and I’ve never seen evidence of a mouse trotting, shuffling, or loping.

Deer and white-footed mice are relatively long-legged and athletic, and they sometimes make long leaps. Voles and shrews, with their chunkier bodies and shorter legs, can’t jump nearly as far. So if you find a trail with leaps like those in the photo below, you can confidently assign it to a mouse rather than a vole or shrew. The tail marks are another clue. Mice have tails as long or longer than their body length. Both the short-tailed shrew and the woodland vole, the two species most likely to be confused with deer and white-footed mice, have very short tails and wouldn’t leave long tail marks like the ones in the photo.

The white-footed mouse trails in the next photo show the typical consistency of pattern and leap length, but the one on the left demands a second look. It begins at the bottom, a little to the right of center, goes upward for a few leaps, and then takes a hard turn to the left. After a few more leaps the trail circles back to the right and proceeds toward the top of the photo where there’s a fallen branch sticking out of the snow (just outside the frame). Each time it turned the bounding mouse flung its tail to the outside for balance, leaving conspicuous tail marks. There’s a pile of snow that was kicked toward the rear where the mouse turned left, and where the trail curves back toward the right the landing/takeoff depressions are deeper. These observations suggest extreme bursts of energy.

We’ll never know for sure, but the most likely explanation is that a threat spooked the mouse. There’s no sign of an actual attack, so the mouse evidently survived, but it must have been alarmed by something. Deer and white-footed mice, along with other small rodents, are in constant danger of predation, and we sometimes find evidence of a successful hunt (see my post for March 1, 2022). But most of the time mouse trails tell us they survived to live another day.

Possum Puzzles

The opossum is a humble animal, slow moving, shy, and generally of a placid disposition. But opossums can present surprising challenges to the tracker, not the least of which is getting a handle on the tracks themselves. To understand opossum tracks it may be helpful to see the animal’s actual feet, so let’s take a look. The photo below shows the underside of the left rear foot of an opossum–it resembles a human hand with a large, widely angled thumb and four additional, finger-like toes. If you hold up your left hand with the palm facing you, you’ll see the resemblance. Try to imagine your hands as the rear feet of the animal.

In the next photo you see the opossum’s left front foot–very different from the rear. The five toes of the front foot are somewhat finger-like and similar to each other in shape, and the middle pads are quite bulbous. Both front and rear feet are adapted for climbing but are less ideal–especially the rear feet–for moving on the ground. This, combined with the animal’s heavy body and relatively short legs, means opossums are not very agile.

Now let’s look at opossum tracks. In the photo below the right front track lies on the left and the right rear track lies behind it on the right, both tracks oriented toward the left. The spreading toe indentations of the front track radiate from a compact grouping of middle pad impressions. In the rear track the thumb points to the side (downward in the photo), and the other four toes are closer together and angled to the opposite side (upward in the photo).

Because the opossum rarely moves faster than a walk (or sometimes a trot), front and rear prints are often partly superimposed, and that’s another source of confusion. (The animal whose tracks are pictured above was drinking at a puddle, so it left some nicely separated prints.) In the photo below you see a left rear and a left front track, oriented toward the right. The two tracks are so close together it’s hard to tell where one ends and the other begins. If you look at the right side of the frame you’ll see five similar toe marks radiating outward from four closely set middle pad impressions. That’s the left front track. The hollow made by the thumb of the left rear track sits just behind the front middle pads, and above it you can see the middle pad and toe indentations of the left rear track.

The indirect register walk is the opossum’s preferred gait, so we often see sequences of front and hind prints like the ones shown above. In the photo below an opossum walked from the lower left to the upper right, leaving the zig-zag pattern typical of the walk. Each angle of the zig-zag is composed of front and rear prints from one side, and in each of these couplets the hind print lies just behind the front print. The sequence of tracks is right rear, right front, left rear, left front, right rear, right front, left rear, left front.

When tracks are less distinct, possum trails can be downright perplexing. The next photo shows another walking opossum trail, again proceeding from lower left to upper right. The rear feet fell farther behind the front feet at each step, but the zig-zag pattern can still be seen. A few of the prints are recognizable as possum tracks, and the rest are just weird looking.

If an opossum needs to move a little faster it shifts into a trot, leaving a trail like the one shown in the next photo (oriented from lower left to upper right). It’s harder to sort out front and rear tracks in this trail because the snow was dry and the faster gait created more disturbance. But if you look closely you’ll see that the rear tracks are consistently just behind the front tracks. The sequence of prints is right rear, right front, left rear, left front, right rear, right front, left rear, left front.

We know it’s a trot because the trail is straighter than the walking trails shown in the previous photos, and the distances between the sets of tracks are slightly greater. There must have been a slight hitch in the gait of the animal that made this trail, because the claws of one of the right feet (it’s hard to tell whether it was the front or the hind) seemed to brush the snow each time it moved forward to the next landing spot.

You may have noticed that none of the possum trails I’ve shown so far have tail drag marks. Opossums don’t drag their tails as often as people may think, but it does sometimes occur. Here’s a photo of a possum trail (oriented from upper left to lower right) with a nice tail drag mark. Don’t worry if the direction of travel isn’t obvious–it’s hard to tell from the photo because of the angle. A fox left a galloping trail on the left side of the frame, moving from bottom to top.

Much of the opossum’s winter diet comes from scavenging on carcasses, and the animals don’t generally move very far away while a food source lasts. So if you come across a possum trail it’s worth following–you may find a feeding site, or even a den like the one shown in the next photo. I had to climb through and around lots of tangles and thickets, but I eventually found the den the opossum was using while it fed on a deer carcass not far away.

Opossum tracks and signs give us a window into the lives of the animals. But I’m fond of them for an additional reason: the tracks are just so quirky. In fact, the consistent peculiarity of possum tracks is one of the clues to their identity. So be alert for weirdness, and when you find it, consider the opossum.

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.

Dust Baths

The photo above (by Rajesh Kalra) shows a house sparrow in the throes of a dust bath. By rolling, wiggling, and scooping up dust with its wings, the bird covers itself with dust, then shakes vigorously to fling the dust in all directions. You can see a dust bathing bird in action here. It’s believed that dust bathing helps to clean dirt and excess oil from feathers and skin, and to suppress parasites. Without this kind of maintenance the bird’s health would suffer and flight efficiency would decline. Dust bathing is a common behavior in many birds.

Once the bath is finished and the bird is gone, the evidence remains in the form of body-sized hollows. Dust baths sometimes appear as roughly circular cleared spaces surrounded by vegetation, as in the photo below. The diameter of the sandy hollow (15 inches) strongly suggests turkey.

Sometimes feathers provide definitive evidence of who the dust bather was. The dust bath in the next photo is ornamented with a few body feathers belonging to a ruffed grouse. There’s also a partial track below the feather. At roughly 8 inches across, this dust bath was the right size for a grouse. The bird had chosen an inactive ant mound, and the finely processed soil was a perfect medium for a good cleansing thrash.

In the next photo you see a dust bath that holds definitive evidence of the bather. A turkey tail feather lies on the lower left side, and a clear track sits in the center. Finding tracks as good as this one is unusual, because they are generally obscured as the bird shakes the soil off. The whole area was large, about three feet across, but the hollow made by the turkey’s body was about 18 inches across.

Some bathing spots don’t seem very enticing. The grouse dust bath shown below was located in a gravel road and couldn’t have been very comfortable. The hard surface must have yielded very little dust, so I wonder how much benefit the bird’s effort yielded. Maybe it was the best site the grouse could find.

Birds aren’t the only creatures that take dust baths. Large herbivores such as bison and elk often roll and wiggle in dusty spots, and small rodents are frequent dust bathers. Rabbits and cottontails also enjoy an occasional roll in the dirt. The next photo shows a snowshoe hare dust bath. Rear tracks show as sets of claw marks on the left and indistinct shapes on the right.

Another mammal that likes to roll in sand or soil is the otter. The animal that made the roll shown in the photo below had just come out of the water, and part of its motivation was to dry its fur. The sand bath also probably helped to clean the otter’s fur and remove excess oil. You can see flattened areas where the sand was pressed down by the otter’s body, and there are some tail marks on the left. The disorganized collection of tracks in the center is interesting. It looks to me like the animal shook itself vigorously to throw the sand off, lifting and placing its feet several times in the process. It then proceeded on its way toward the top of the frame.

Dry, loose substrates are preferred for dust bathing. Dusty roads or trails, sandy deposits, fine humus, and decomposed logs are likely places to find dust baths. Small birds and mammals often choose hidden locations for their hygienic activities. Turkeys usually establish dust baths in open sites where escape is not hindered by obstacles. But wherever you find them, you should check out any strangely hollowed or cleared spots you come upon. You might have found the location of a seldom seen part of a wild creature’s life.

Red Squirrels and Norway Spruce: A Special Relationship

The staccato warning call of a red squirrel is a common sound in our northeastern forests. These feisty animals are extremely protective of their territories, and they seem to react to the presence of people as much as to other squirrels. Red squirrels are found in both hardwood and coniferous woodlands, but their numbers are highest where there are extensive stands of conifers. In the Northeast one of their favorites is the Norway spruce (Picea abies). These majestic trees are native to northern Europe, but were planted extensively during the 19th and 20th centuries. Their tolerance of poor soils made them ideal for degraded sites, and many stands were established on abandoned farm land during the Depression.

Open grown Norway spruce trees are impressive for their height and form. The specimen shown above exhibits the large cones (up to 6 inches long) and the drooping branchlets that help to differentiate Norway spruce from other spruce species. In plantations the huge cones littering the ground reveal the tree’s identity, and even fairly young trees show drooping branchlets like those in the next photo.

Red squirrels feed on the cones of many different conifers, but they find the large fruits of the Norway spruce especially attractive. Cones are stored in underground larders and supply the animals with sustenance over the winter and often well into spring. Red squirrels like to feed on perches, and in winter they favor low branches located above or near their larders. Years of use can result in impressive middens of discarded cone scales and cores like the one below.

Conifer cones reach maturity in late summer, and the period between the exhaustion of the previous year’s provisions and the ripening of the new crop can be a lean time. Tree buds, berries, underground tubers, and insects help to carry red squirrels over this stretch, but conifer cones are their go-to choice. For most conifers species the cones don’t provide much nutrition until they have reached nearly full size, but Norway spruce is different. Because of their size, even immature cones attract hungry red squirrels. I’ve found evidence of red squirrels extracting tiny seed meats from the current year’s cones as early as late June. At this stage logs and stumps are often used as feeding perches. The red squirrel that left the remains in the next photo found a perfect picnic table.

In the close-up below you see the partly processed cone and some of the cone scales and seed remnants. Squirrels work on cones starting at the base, tearing off each scale and biting a hole in each seed coat to extract the nutritious contents.

Sometimes the accumulations of cast-off cone scales and seed remnants can be quite colorful. In the photo below there’s a pile of cone scales in the upper left and a scattering of winged seeds in the center. At the very top of the frame you see the outer aspect of several scales. Their exposed tips are bright green and the parts that were overlapped by the scales below are tan or reddish. Below and to the left of those, there are several scales with their inner sides showing. The green ovals outlined with red show where the seed wings were positioned. In the center of the photo you see what remains of the seeds, tan seed coats attached to the maroon seed wings. Ragged openings in the seed coats show where the meat was extracted.

The next two photos show the inner aspect of a single cone scale. In the first shot there’s one winged seed on the left, still lodged where it formed. The squirrel extracted the meat by biting into the base of the seed without displacing it. For the next shot I removed the seed so you can see how it rested against the inside of the scale.

As red squirrels begin to feed more and more on the current season’s cone crop, brightly colored discards pile up on the brown remains from previous years.

In a month or so red squirrels will begin the serious business of putting up stores of cones for the coming winter (see my post, Bounty From Above, September 14, 2020). If you do some investigating when you come across stands of Norway spruce you’ll get a look into the lives of red squirrels and the seasonal cycles which have shaped their behaviors.

Streamside Discoveries

As the high water levels of late winter and early spring subside, stream and lake margins become interesting tracking locations. Water is a magnet for wildlife, and visiting creatures leave the evidence of their activities along the shoreline. A great blue heron left the collection of tracks shown in the photo below. The feet of herons resemble the feet of songbirds, with one backward-pointing toe and three forward-pointing toes. But unlike most songbirds, the toes of herons don’t all meet at one point. There’s a left print (facing toward the lower right) in the upper left corner of the photo that shows this nicely. The junction between the backward-pointing toe and the inner forward-pointing toe lies to the left of the intersection between the two outer toes. Another way of saying this is that the two outer forward-pointing toes join a little to the outside of the center of the foot. The same asymmetry shows in the right track in the lower right corner.

The spotted sandpiper is another bird that patrols stream and lake margins. These small birds–about the size of a starling–search for invertebrates on the edges of streams, ponds, marshes, and other bodies of fresh water. Their tracks (shown in the next photo) reflect their erratic and meandering movements. The three forward-pointing toes are relatively symmetrical and diverge at wide angles. On the back of the foot there’s short spur oriented to the inside that may or may not make an impression in tracks. The left print just below the stick in the upper right corner shows the spur nicely.

Raccoons prefer comfortable surfaces so it’s no accident that the animal that left the tracks shown in the photo below stepped along a soft deposit of sand left by a recent flood. The raccoon moved from the upper right to the lower left, leaving tracks in the sequence right rear, left front, left rear, right front. The difference between the wider but tighter rear track and the narrower, more spreading front track is easily seen in the set of prints at the upper right. Raccoons habitually work the edges of streams and ponds where they find tasty shellfish, frogs, crayfish and other invertebrates. The pattern of alternating sets of hind and front tracks from opposite sides tells us the animal was moving at a pace-walk.

Mink are also in the habit of travelling along the margins of water bodies. The animal that made the tracks in the next photo was moving from right to left at a lope, and the track sequence is right front, right rear, left front, left rear. Like raccoons, mink have five toes on both front and rear feet, but it’s not uncommon for the impression of the inner toe to be missing. In fact the only print in the photo that shows a clear inner toe is the left front. This track also shows the middle pad protuberances (just behind the toes) and the heel pad (the small indentation behind the middle pad). Mink share a taste for crayfish, frogs and invertebrates with raccoons, and occasionally catch small fish. They’re adaptable predators and may also hunt for small mammals on the surrounding land.

The mink’s larger relative, the river otter, also leaves its tracks along the edges of ponds and streams, but for this creature it’s mainly a matter of convenient travel between feeding areas. I found the tracks in the photo below on the inside of a bend in a stream where an otter had taken a short cut across a large sandbar. The sequence of tracks is the same as that of the mink tracks in the previous image, and the family resemblance–both mink and otters are mustelids–can be seen in spite of the different substrates. Otters are more aquatic than mink and capture most of their food in the water.

When they’re not foraging in the water otters spend their time on conveniently accessed sites near the water. They roll on soft surfaces like grass and forest duff to clean and dry their fur, and they socialize with other members of their family group. They also leave notices in the form of scat to non-resident otters that the territory is occupied. The otter scat in the photo below contains crayfish shell fragments, but it’s also common to find scats containing fish scales and bones, or the slimy remains of frogs. Otters often use latrines where scat of various ages and contents can be found.

The beaver is another very aquatic mammal. In the photo below you see two beaver tracks, a right front (above) and a right rear (below), both facing toward the right. In the front track the four toes show clearly and the two heel pads appear as elongated grooves because the foot slipped in the mud. In the bottom part of the frame the three outer toes of the hind print show clearly but the two inner toes are obscured by the front print. As is often the case, the webbing of the hind foot doesn’t show. The size difference between the front and rear tracks is striking and helps us to understand why beavers are such strong swimmers. Beavers feed on the leaves, bark, and stems of woody plants year-round, but during the growing season the diet also includes aquatic plants, cattails, sedges, and forbs. Their tracks usually lead between the water and foraging sites on land, and signs of branches being dragged into the water are common.

Smaller–but just as well adapted to life in water–is the muskrat. Like the beaver, the muskrat has rear feet that are much larger than the front. In the photo below, the track farthest to the left is the right rear, and just to its right you see the right front. On the right side of the frame the left rear lies below the left front. Notice that the small inside toes of the front feet made impressions in both of the front prints. The muskrat’s front feet, like those of the beaver, are adapted for handling food items and building materials rather than for swimming.

If you wander along shorelines you may find muskrat latrines. These sites are usually located on logs or rocks that lie in the water but protrude above water level. In the next photo you can see a rock decorated with scat of varying ages, deposited as an announcement that the territory is occupied. Although muskrats occasionally consume animal foods they are primarily plant eaters, and their scats usually contain fibrous material.

This is just a sampling of some of the wonders to be found along the margins of lakes, streams, and marshes. There’s always something to be discovered, so next time you’re out and about, take a detour to check a stream edge or a muddy shoreline. Better yet–if you don’t mind some wading–try a stream walk. It could be just the thing on a summer day.

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.