Category: animal signs

Ruffed Grouse Snow Beds

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

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

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

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

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

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

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

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

Black Bear Days

Black bears habitually cover great distances in search of food, moving from one source of edible treasure to another throughout summer and fall. The animals often find our trails and primitive roads to be convenient travel routes, and the muddy spots that develop in rainy weather are an ideal medium for capturing their tracks. I recently found these tracks on a forest trail used by snowmobiles and ATVs. The direction of travel is to the left; the left rear print is at the lower left and the left front is at the upper right. Bear tracks, especially those of the hind feet, may remind you of barefoot human tracks, but beware–the largest toe lies on the outside of a bear’s foot rather than on the inside.

But even when there’s no mud, you can learn a lot about the daily lives of bears by observing the sign they leave. Bears love fruits of all kinds. The bear that climbed the shadbush trees pictured below probably knew they wouldn’t support its weight. But no matter, it was easier to eat the berries while standing on the ground anyway.

When apples start to ripen, bears climb the trees to get to the sweet fruits in the highest branches. The gouges in the photo below show how the bear’s claws slipped downward before they caught firmly enough for the animal to move farther upward. When feeding on apples or other fruit, bears sometimes break branches and leave them hanging in the tree or on the ground below. Smaller animals like raccoons and gray foxes also climb trees in search of fruit, but their claw marks are narrower and do not show the separation distances of one inch or more that are typical of adult bears.

Insects are a much sought-after source of protein, and bears dig up nests and tear open logs and stumps to get at grubs and larvae. Even whole tree trunks are not too much for a bear’s power. The snag in the photo below was dismembered by a bear. No other animal would have been able to break out the large sections of wood and scatter the fragments in several directions.

It’s not always possible to determine exactly what a bear was after, but in the case of the tree above the evidence–the remains of carpenter ant galleries shown in the photo below–was still present in the large wood sections. Carpenter ants don’t actually eat wood. Instead they use trees as nest sites, and the tunnels and galleries they create in dead wood serve to house their eggs and larvae. Once an ant nest is exposed by a marauding bear the adult ants flee, but the eggs and larvae, and probably a fair amount of wood, are scooped up and consumed en masse.

Bears are also concerned with the movements of other bears, and they keep tabs on each other through various kinds of messages. The bites which decorate the balsam fir shown below were made by a bear standing on its hind legs. To leave such marks a bear sets an upper canine tooth in the bark and draws the lower canine in. This leaves dot-dash patterns like those to the left of the debarked area. The debarked area itself resulted from repeated biting, and the weathered appearance of the exposed wood tells us that the marking had been going on for a number of years when the photo was taken. Such marks may be visible to bears at close range, but more importantly, they hold the scent of the animal which made them, and bears are famous for their keen sense of smell.

This was a large tree, and it must have been a magnet for every passing bear. It stood about twenty feet off of a seldom-used hiking trail, and between the trail and the fir tree there was a narrow passage with distinct step spots. These step spots were created when approaching bears walked toward the tree with an exaggerated swagger, planting each foot deliberately as if they wanted to leave as much evidence of their visit as possible. In the photo below the step spots show as brown areas of bared soil.

Bear sign, and sometimes tracks, can be very abundant, but unless there’s an artificial attractant (such as garbage or handouts) they’re seldom seen. But fortunately for us their strength and resourcefulness can be observed in their tracks and sign. We can even read, albeit on an elementary level, their messages to each other.

Turtles on the Move

One spring a few years ago, as I wandered along the banks of my local stream, I came upon a wood turtle engaged in digging a hole in a gravel bar. She was preparing to lay eggs, and she seemed to be laboring mightily. The spot was very rocky and she wasn’t making much progress.

Finding a turtle in the process of egg laying isn’t that common, and wood turtles themselves are scarce, so this was a very exciting find. But not wanting to create any more difficulty for her, I took a few photos and left. I don’t know whether she succeeded or whether she gave up and looked for an easier location.

Turtles usually find places that are more favorable for digging, like the sandy spot in the photo below. But the eggs in that nest didn’t mature. When young turtles hatch successfully they break out of their shells underground and make their way to the surface without creating much disturbance. The presence of signs of digging and shell fragments on the surface means that the nest was raided and the eggs were eaten, perhaps by a raccoon or a fox.

Although late spring and early summer are the peak times for reproduction, turtles may continue to mate through the summer and even into the fall. Pairing up and egg laying generally involve a lot of travelling, and these wide-bodied and low slung animals leave distinctive trails. The trail below was made by a diamond-back terrapin moving from bottom to top. Each line of impressions was made by the front and hind feet on one side, and the small front tracks alternate with the larger rear tracks. Between the two strings of prints you can see disturbances made by the dragging plastron, and at the very bottom of the frame there’s a small tail mark.

This turtle was walking, but the pattern looks very different from the patterns we see in walking mammals. That’s because the terrapin’s wide body and short legs prevent it from walking the way most mammals do. The turtle was doing an understep walk, the rear foot consistently coming down behind the spot where the front that moved forward just ahead of it was placed. The rear feet touched down about midway between the last front track and the one before that, so the spacing between prints is roughly even.

Here’s another turtle trail, this one made by a painted turtle moving from top to bottom on hard sand. The tracks consist mainly of claw marks, and they lie in sets of two, each set made up of a front followed by a rear. Both front and rear feet have five claws, but the front prints turn inward while rear prints point straight ahead. The gait in this photo is also an understep walk, but the hind tracks are closer to the front tracks than in the preceding example. Although the relative positions of front and rear prints can vary, turtle trails are always variations on the understep walk.

The trail in the photo below was made in dry sand, and the dragging plastron made a wide, smooth mark between the two track lines. Clear prints are not present, and it’s not obvious which way the turtle was going. Two kinds of evidence suggest that the direction of travel was right to left. First, the plastron drags seem to have smooth slopes on their right sides and steep edges on their left sides. And second, the deep holes made by the feet have drag marks pointing to the left.

Turtles are on the move, and their journeys can take them through a variety of habitats. Any area of sand, silt, or mud might show their unique parallel strings of prints and, sometimes, whimsical designs. So when you get a chance, take a detour and check out that patch of sand or muddy shoreline.

Avian Woodworkers

Woodpeckers, like other birds, are raising families at this time of year, and they’re consumed by the need to provide food for their young. Because they find much of their food in the bark and wood of living and dead trees, their feeding sites are usually easy to find. The first clue is often a pile of wood chips scattered around a tree base, like the accumulation at the base of the beech tree shown below.

This tree was alive but just barely–the cankers on the trunk tell us it was infected with beech bark disease. The two excavations visible in the photo, plus many more higher on the trunk, were the sources of the widely scattered debris below.

If your timing is good you may find woodpecker scat among the chips. Here’s a close up–this scat was about 1/4 inch in diameter, contained insect exoskeletons, and had some white uric acid on the mostly black surface. Woodpecker scats are delicate and disintegrate when they’re rained on, so you’re only likely to find them in fresh debris piles.

The cavities below were made in a Norway spruce that was very much alive. New holes are often circular, but as they’re enlarged they become elongated and sometimes connect to form long troughs.

So what exactly are woodpeckers that attack trees eating? Contrary to what you might think, they aren’t eating wood! The photo below shows a close-up view of an excavation. Deep in the recesses of the hole the wood is partially decayed, and you can see that it’s honeycombed with tunnels and chambers. These are the galleries of carpenter ants. They’re actually nests rather than feeding sites–carpenter ants range widely on plant surfaces and on the ground, eating other insects as well as sap and nectar. Both living and dead trees may house carpenter ant colonies, and there could be thousands of ants in one tree, so for a woodpecker it’s well worth the work of excavating holes to get at them.

The photo above also shows cuts and grooves made by the bird’s beak as it chiseled the wood away. These beak gouges are large, up to one half inch wide. The pileated woodpecker, the largest and most powerful of our woodpeckers, was responsible for all of the examples shown above. Only a bird this size could make such large holes, not to mention create such wide beak gouges and leave such large scat.

Although smaller woodpeckers can’t produce the same kinds of massive excavations, they still manage to find plenty of food in the bark and outer wood of trees. Hairy or downy woodpeckers searching for wood-boring grubs removed patches of bark from this hemlock tree.

And the dead maple shown below was also mined for wood inhabiting insects. It’s covered with pockmarks made by smaller beaks, as well as some larger gouges, so it was probably a multi-species feeding site.


Wood, whether living or dead, may host many different types and sizes of insects, including the wood-boring larvae of beetles and moths, insects that nest in wood, predatory arthropods that feed on other wood-inhabiting insects, and creatures that simply find shelter in cracks and crevices. Thanks to this diversity, wood is a rich source of food for many different birds.

Red Squirrel Housekeeping

The snow is gone and leaves have not yet filled in the forest canopy, so it’s a great time to look at red squirrel middens. Conifer seeds make up a large percentage of the red squirrel diet, and the animals spend lots of time eating or collecting conifer cones. To get at the seeds a squirrel holds a cone in both front feet and, starting at the bottom, chews off each scale and eats the exposed seeds, spinning the cone as it works its way toward the tip. This is done with typical red squirrel energy, and the scales seem to fly out at blistering speed. The scales and cone cores accumulate around or below the feeding station, and the resulting piles of debris, called middens, can be quite sizable. The mounds in the photo contain mostly the cores and scales of Norway spruce cones. Middens this large must have accumulated over a number of years, probably during the residence of several different animals.

The hole just below the trunk of the closer tree is an entrance to an underground space where cones were stored. These food caches are often located in the spaces around the roots under the middens, but may also be in rock cavities, log piles, or even human structures. They are generally underground where the high humidity prevents the cones from opening.

Red squirrels depend on stored conifer cones for survival over the winter. In late summer and early fall conifer stands resound with the sound of objects hitting the ground as the animals nip the cones in the tree tops. Once a good supply has fallen, the squirrels descend and carry the cones to their underground storage spaces. It’s this habit of creating concentrated supplies in a limited number of locations, called larder hoarding, that allows the animals to inhabit boreal forests with long, snowy winters. Imagine the effort that would be involved if, like gray squirrels, red squirrels had to dig down through a deep snowpack to retrieve each individual food item. With its food stored in larders a red squirrel merely needs to maintain tunnels leading from the surface to the ground-level entrances.

Middens are usually located at the bases of the trees which provided the cones, indicating that the squirrels bring cones up from storage to perches higher in the tree to feed. In the photo above you can see a Norway spruce with several branches (dead but still strong enough to support a squirrel) which could have served as feeding perches. These branches, or ones nearby, are often marked by the squirrels. One such branch is shown in the photo below. The shot was taken from directly above the branch. You can see some partly eaten spruce cones on the ground below in the upper part of the photo, and the dark tree trunk in the lower right-hand area. The branch itself is liberally marked with the fresh gouges of red squirrel incisors, and there are a few older gouges from previous years. The scent compounds left in the wood would establish the resident squirrel’s ownership of that particular real estate.

Middens tell us how much red squirrels depend on conifers for their winter food supply–and it’s not just Norway spruce. Where pines, hemlocks, firs or other spruce species are more common their cones provide the bulk of the winter diet, and similar middens can be found.


In the mixed forests of central New York, middens tell us about the non-coniferous foods that red squirrels also make use of. In the photo above butternut shells with typical red squirrel entry holes are mixed with the spruce scales and cores. I’ve also found the opened shells of walnuts, acorns, and hickory nuts in red squirrel middens. And occasionally a bone fragment, with telltale incisor gouges, sits atop a midden. Red squirrels, like other small mammals, need to boost their calcium intake by chewing on bones, and a familiar feeding perch makes a fine location for a dose of minerals.

Spring Fever among Woodchucks

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

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

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

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

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


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

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

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

Squirrels Share Some Secrets

I’ve been getting more and more interested in squirrels. Like all animals, their lives are shaped by the seasons, and there’s much to discover if you can find and decipher the signs they leave. In late summer squirrels bite off oak twigs to get at the ripening acorns, and the “nip twigs”  (minus acorns) can be found scattered under oak trees. The acorn remnants–shell fragments and partly eaten acorn meats–may also be found on the ground or on nearby logs or stumps where a squirrel has a good view of its surroundings while feeding.

In September I found these apparently uneaten acorns, along with cap and shell fragments, scattered on the ground beneath some red oak trees. The acorns were intact, but every one was marred by brown spots. This puzzled me at first, so I got out my magnifier and took a closer look. I noticed that there were tiny tunnels in some of the brown spots, and one even had a minute, worm-like insect larvae. I also saw indistinct gouges in a few of the brown spots that looked a lot like tooth marks. Mystery solved! The squirrels were feeding on acorn weevils, often found inside acorns and much richer in calories than the acorns themselves.

We’ve had a very wet fall, and fungi have been popping up everywhere. I’ve been surprised to see how fond squirrels are of mushrooms. I’ve repeatedly come across mushrooms which had been plucked from where they had grown, carried to some other spot, and partly or almost completely eaten. Bite marks sometimes showed along the edges, and there were always discarded pieces scattered around–squirrels seem to be sloppy eaters. Slugs and snails also seem to love mushrooms, but they simply make broad, shallow gouges in the caps and the mushrooms remain standing where they grew.

When the weather turns colder squirrels give up their summer leaf nests and move into more sheltered lodgings, often in hollow trees. Instead of using leaves, they line their nests with fibrous material. The inner bark of this dead branch was stripped off by a squirrel and used to provide warm insulation for its nest. The smoothly denuded wood surfaces and hanging remnants are typical of squirrel work. In addition, there are usually a few gouges made by the animal’s incisors somewhere in the debarked area. Dead branches are the most common source of good nest lining material, but the bark of living honeysuckle and other shrubs is a favorite material where they are available.

You may have been wondering which squirrels I’ve been talking about. Actually, I’ve purposely avoided naming them because I’m often not sure. Our mixed forests host both red and gray squirrels, not to mention northern and southern flying squirrels, and it’s often difficult to know which species left a particular sign. I suspect that the oak nip twigs and the weevil feeding were done by gray squirrels, but red squirrels also feed on acorns. I’m pretty sure both red and gray squirrels eat mushrooms, and all of our squirrels line their winter nests with fibrous material. There are some types of sign–certain kinds of marking, and large middens under conifers–that can definitely be attributed to a particular species; more about those in future blogs. Until then, we’ll adopt the wise tracker’s attitude and recognize the limits of our certainty.

Busy Bears

I just spent a wonderful week in the western Adirondacks, and I was able to indulge in one of my favorite activities: exploring the Independence River on foot–in other words, wading. Besides being breathtakingly beautiful, the Independence is small enough to be safely waded when water levels are low, and there are plenty of sandbars and silty edges where tracks can be found. These bear tracks were the find of the day. The bear was traveling from left to right, and my dog (she likes to explore rivers with me) left tracks below the bear’s,  going in the opposite direction. The first bear print at the upper left is the right front, and just to its right is the right rear. A little farther to the right is the left front print and to its left the left rear. The pattern of rear print ahead of front from the same side tells me that the bear was moving at an overstep walk–a gait often used for relaxed investigation or leisurely travel.

I was excited to find bear tracks because they’re not always easy to find, especially in late summer when the animals are spending much of their time in forests, overgrown clearings, or other relatively untrackable places. The bear may have visited the river to drink, or perhaps to use the shoreline as an easy travel route to a new food source. But even if there are no tracks to be found, there are usually plenty of other indicators that bears are in the neighborhood. Bears use a variety of marking techniques to communicate with other bears, and these marks are often prominent and long-lasting. A bear raked this white pine tree with its claws, leaving fresh claw marks which oozed with copious sap flows.

Man-made structures like signs and lean-tos are often targets of bear marking. On a different day during my recent visit to the ‘Daks I walked along a forest road where posts had been set to mark the locations of culverts. It was clear that bears were habitually using that road–many of the posts, like this one, were ravaged by bear bites. The brighter wood exposed by the bites stands out to our eyes, but for the bear the scent of the saliva-soaked wood is probably more important.

Teeth and claws aren’t the only things bears use to make their presence known. They often rub against trees or wooden structures leaving a personal scent signature from the oils and sebaceous chemicals in their fur. Another post along that same forest road was decorated with hairs left by a bear that had done just that.

And then there’s always scat. Piles of bear scat provide long-lasting samples of what bears are eating. This time of year in the Adirondacks black cherries are a favorite item, as demonstrated by this example. Elsewhere the skins and seeds of apples, grapes, viburnums and berries; squash and pumpkin seeds; corn kernels; or the shells of hickory nuts, beechnuts and acorns may show up in late summer scat. This is the season of ursine hyperphagia, the insatiable hunger that drives bears to eat almost 24 hours a day. The thick layers of fat they put on will allow them to survive their long winter hibernation.