This is the time of year when it pays to watch where you walk – there are a number of ground nesting birds, some of which, including killdeer, may choose your lawn or even your garden to build their simple “scrape” nest. Typically killdeer nest on the shoulders of roads, gravel roof tops, fields and gravel parking lots. The nest is very primitive, and there’s actually very little to it — killdeer scrape a slight depression in the ground, to which they often add bits of material, including white objects such as shells and bones. Their pigmented eggs are extremely well camouflaged. The young precocial killdeer chicks are on their feet and feeding themselves as soon as their down feathers dry. (Photo by Sadie Richards)
This is the time of year when two-year-old beavers leave their lodges and strike out on their own, primarily because the woods surrounding a pond usually can’t support more than one family of beavers. Beavers are exceptionally territorial; once they’ve established a lodge, they do not take kindly to interlopers. In order to make this perfectly clear to house-hunting young beavers, in the spring resident beavers build what are called scent mounds — piles (up to three feet in height, but usually much smaller) of mud, leaves and pond-bottom debris — around the perimeter of their territory. They then smear castoreum, a substance that comes from their castor sacs, over the mound. Chemicals in the castoreum convey to roaming young beavers that this particular pond is spoken for.
Many mammals have two molts a year, producing a winter and summer coat. Moose only have one annual molt, and it occurs in early spring. Their winter coat consists of long (up to six inches on neck and shoulders), hollow guard hairs and a thick undercoat. In early spring the faded and ragged winter hairs are shed and replaced with short, dark, shiny hairs. Molting starts on the shoulders and proceeds along the sides of the neck and back over the moose’s body. Adult bulls molt first, the cows and yearlings shortly after. Pictured is a beaver-cut tree which was used by a moose to scratch off loose winter hair.
A cooper’s hawk made short work of a mourning dove near my bird feeder recently, killing and apparently, given the large number of feathers scattered on the snow, plucking the dove on a nearby snow bank. If you look closely you can see whole sunflower seeds in amongst the feathers. These came from inside the mourning dove’s crop. Mourning doves generally feed quickly, filling their crop with seeds which they digest later, when they’ve found a safe spot in which to roost. Unfortunately for this particular dove, it didn’t live long enough to have that opportunity.
A study of coyote prey (through stomach contents) in the Adirondack Mountains of New York revealed that beavers were second only to white-tailed deer. This photograph shows that, possibly for the last time this winter, a coyote recently took advantage of a still-frozen-but-fast-thawing pond by walking across it in an attempt to reach an active beaver lodge. Once there the coyote attempted to dig into it in order to reach the inhabitants. A hard, two-to three-foot-thick wall of frozen mud, logs and sticks kept the beavers well protected, as it was designed to.
If you find clumps of empty burdock fruits lying on top of the snow, there may well be wild turkeys in the area. During the winter, especially when the snow pack is deep, wild turkeys feed on vegetation poking up above the surface of the snow, such as burdock seeds. There are tell-tail signs when turkeys have been eating burdock, even if no tracks are evident, because of the way in which they consume the seeds. Turkeys somehow pluck the burdock fruits off and then turn them inside-out, exposing the seeds which they then eat. Typically several of these empty fruits will be “velcroed” together, leaving small bunches of them scattered over the snow.
It’s often a lot easier to find signs of otters than otters themselves. Recently I discovered two dead crayfish on the shore of a mostly iced-over pond that I knew was inhabited by otters. Nearby otter scat confirmed that these crayfish were probably left by satiated otters. The most important prey item in a majority of otter scat analysis studies is fish, followed closely by crayfish. Otters will take advantage of other prey, such as frogs, salamanders, ducks, muskrats, an occasional young beaver, mice, snakes, insects and even turtles when readily obtainable, but fish and crayfish are first and second choices.
If you walk in many of New England’s woods, it is likely that you will come upon deer tracks. If the snow isn’t deep enough to keep the deer confined to one area, or “yard,” such as this year, then tracks can often be found throughout the woods. Where there are tracks, there are also beds – spots, often on higher ground, where deer bed down for the night. By looking at the edges of the indentation left when a deer lies down, you can usually determine which direction the deer was facing. (It’s back leaves a fairly symmetrical curve in the snow, and its knees often make impressions.) Deer frequently travel in herds and bed down together. Because they are prey for numerous animals, it should come as no surprise that their actions, even ones as simple as in which direction to lie down, are intentional. If you look at an area where several deer bedded down, you will usually find that each deer is facing a different direction. This is so that, together, they have as much of a 360 degree view as possible, in order to spot an approaching predator. The deer that occupied the closest bed in this photograph was facing right, while the further deer was facing left.
Otters will travel long distances from one pond to the next, and when they do, they frequently alternate between bounding and sliding. They often slide down hills, but they also slide on level ground, as in this photograph, and sometimes even uphill. While sliding, the otter holds its front feet back along its sides with its hind feet out behind it, leaving a trough roughly 6” to 12” wide and up to 25 feet long. Two footprints (actually four, but the hind feet land on top of where the front feet landed so it looks like two) can be found at the end and at the beginning of each slide, where the otter stopped sliding, bounded and began sliding again. You can see at least five separate slides in this photograph. Occasionally, in deep snow on level ground, an otter will use its foot to help push it along, either inside or outside of the trough. Otters slide at all times of the year, on mud as well as snow and ice, and appear to do so in order to get from one place to another, as well as purely for fun, as when they repeatedly slide down the same slope over and over. (Thanks to Mark and Susan Boutwell for sharing their discovery.)
It is not coincidental that you often find otters residing in beaver ponds. There appears to be a commensal (one animal benefits while the other is unaffected) relationship between these two animals. The beaver is unaffected – it is a herbivore, so its food supply is not threatened by the presence of otters. (While an occasional beaver is eaten by an otter, it is a rare occurrence.) The otter, on the other hand, benefits from abandoned as well as active den sites (both beaver bank dens and lodges) as well as an ample supply of fish due to the impoundment of streams by beavers. While I was aware that otters often take over abandoned beaver lodges, I only recently learned that the lodge does not have to be uninhabited for otters to move in. This was confirmed when I discovered a large amount of otter scat (mostly fish scales and crayfish shells) on top of a beaver lodge, right next to the hind foot print of a beaver. Freshly placed sticks on the lodge (it is in open water) indicated that it was occupied by beavers, while an otter’s stream of air bubbles could be seen as it exited the lodge and popped its head up above the surface of the water.
At least one porcupine got a jump on humans this sugaring season. A porcupine eats outer tree bark in order to access the phloem (layer of inner bark cells that transport nutrients) and cambium (produces phloem and xylem cells) layers of a tree, its primary winter diet. In eating these layers, the porcupine unintentionally cuts into the xylem, or sapwood, where water and dissolved minerals (sap) are transported between the roots and crown of the tree. Unintentionally, porcupines tap the trees whose phloem and cambium they eat. In this case, the weather had warmed up enough to cause pressure in the tree, which in turn caused the sugar maple’s sap to flow just as a hungry porcupine happened along. Soon thereafter, the temperature dropped, causing the sap to freeze, forming icicles. While they looked good enough to sample, one whiff of them told me that sap was not their sole ingredient! (They were located beneath the porcupine’s den in a hollow tree, from which urine flows freely.)
I have never heard of this particular fisher hunting technique, nor have I seen or read about it before, but there’s no denying that a fisher made these marks in the snow and that they tell the story of how it captured a mouse or vole. It’s likely that the fisher could hear or smell that the rodent tunnel in the subnivean layer was occupied. It looks as though the fisher methodically scraped snow towards the center of the circle, going completely around the tree in an attempt to trap and/or expose the mouse or vole within the circle. It succeeded in opening up the rodent tunnel (the hole is in the dead center of the photograph), and if the tiny droplets of blood on the snow near the hole are any indication, was successful in capturing its prey.
Striped skunks are nocturnal and, for the most part, semi-dormant in the winter, especially during cold spells. The females often gather in communal dens in groups as large as 15. Come mid-February the polygamous males become very active, searching far and wide for mates. Although the mating season doesn’t peak until mid-March, tracks throughout woods and fields confirm that the breeding season is in full swing. During a typical night a skunk may cover ¼ to ½ a square mile, but during the breeding season, this increases to 4 or 5 square miles.
If beavers have bank dens on rivers that remain open all winter, they are not subjected to the confines of a dark, damp lodge for several months. They have access to fresh food year round, and aren’t limited to the pile of aging branches under the ice that they stored last fall near their lodge. On the other hand, beavers that do live in ponds that freeze over often can find an opening in the ice if there’s a big enough January or February thaw. In either case, signs of their activity on land can be found.
A pileated woodpecker’s diet often shifts with the seasons. One study found that the primary food of these woodpeckers was fruit in fall, carpenter ants in winter, wood-boring beetle larvae in early spring, and a variety of insects in summer. During the winter, with the help of its impressive beak, the woodpecker pries off long slivers of wood from trees containing carpenter ants and exposes the ant galleries. It then uses its long, pointed, barbed tongue and its sticky saliva to catch and extract ants from the ant tunnels inside the tree. This winter diet can be confirmed by examining the contents of a pileated woodpecker’s droppings. Finding these droppings is simply a matter of locating a tree that has a considerable pile of wood chips at the base, indicating that a pileated woodpecker has spent a lot of time working on the tree – long enough to have deposited droppings in and amongst the chips. The droppings crumble easily and reveal a multitude of tiny, black, shiny carpenter ant body parts. (The whitewashed end is due to uric acid.)
If you look up occasionally when you are in a beech-maple forest, you may observe a sizeable cluster of twigs and branches fairly high up in an American beech tree. This “nest” of twigs is usually bigger than any squirrel’s nest and not cup-shaped like a hawk or owl’s nest. In fact, it isn’t a nest at all – it is a sign that a black bear has been sitting, usually in the crotch of the tree, pulling, biting and breaking off branches primarily in order to eat nuts (leaves, buds and catkins are also consumed). When the bear is finished eating what it desires, it discards the branch into a pile. Although known as a bear “nest,” this pile of branches is not a resting spot for bears. If you’re not convinced that a pile of twigs you find was made by a bear, and if it’s in a beech tree, try looking for claw marks on the smooth bark. If it’s a bear “nest,” you’ll most likely find some! (Discovery by Alfred Balch)
For the past two to three months, coyote courtship has been taking place. Both males and females have been marking more frequently, and male coyotes have been traveling further than usual in search of a mate. A female has marked the top of the stump in the photograph – you can see the foot prints she made as she squatted to urinate. The blood-tinged urine indicates that she is in estrus, or heat. With luck, you might hear the duet of a male and female coyote that is sometimes sung just prior to copulation.
At first glance, this looks like any other kill site, but if you look closely at the hairs, you’ll see that it was a striped skunk that was preyed upon – a rare find, for two reasons. One is that striped skunks spend most of the winter holed up and only amble out during warm spells (which we had recently). Their mating season is also about to begin. The second reason that this find is unusual is that skunks have very few predators, for obvious reasons. Great horned owls and occasionally a coyote, fox or bobcat will risk being sprayed. In this case, tracks were not evident by the time it was discovered. Initially the lack of anything other than hair suggested that the predator was a mammal which carried off the skunk (great horned owls usually eat at the kill site). However, it turns out that the absence of bones, etc. doesn’t actually rule out an owl. According to the Cornell Lab of Ornithology, occasionally when a great horned owl kills more prey than it can eat, it caches the remains for later use. When in need of food, the owl will incubate frozen prey until it thaws and can be eaten. (Discovery and photo by David Putnam.)
A recent exploration of some rocky ledges, a favorite winter denning site of porcupines, revealed a virtual maze of trails leading to roughly a dozen crevices where porcupines sought shelter. A look inside these crevices confirmed that porcupines leave something to be desired when it comes to keeping house. Unlike many other animals that keep their dens pristine (e.g. beavers only defecate in water, never in their lodge), porcupines don’t feel the necessity to roust themselves when nature calls. As a result, the floor of their den consists of years of accumulated scat (and urine). In some cases, the pile of scat in these ledge dens was so high that it made you wonder how a porcupine could even fit into the crevice, and indeed, in some cases, porcupines do have to dig their way out of their den. When it became aware of my presence, the pictured porcupine assumed its characteristic defense posture, exposing its quill-filled back and upper tail surface to the intruder. It needn’t have worried, as the opening was barely wide enough to get the camera into, much less the photographer!
A trail of ruffed grouse tracks in the snow led me to the spot where two grouse had bedded down for the night behind a fallen tree. With snow too shallow to burrow into, this was as protected a location as they could find. More often than not, a grouse defecates in its night roosting site before leaving in the morning. Grouse scat comes in two forms, one a dry, fibrous cylindrical pellet with a white-wash of uric acid at one end, and the other a softer, darker brown plop. The vast majority of a grouse’s diet (buds, twigs, leaves, catkins) goes directly through its digestive system and forms the dry, courser scat. Finer (and more nutritious) material such as the cambium layer of woody plants enters the caeca, two specialized pouches, before passing through the large intestine. The caeca contain bacteria which break down cellulose and produce the more digested, and therefore more liquefied, scat. Sometimes the two kinds of scat are deposited separately and sometimes, as in the bed on the right in the photograph, together. (Thanks to Dr. Alcott Smith who clarified grouse digestion for me.)
Even with the knowledge that the moose is the largest member of the deer family, the discrepancy between the size of its hoof and that of a white-tailed deer’s is impressive. A moose’s front foot track is somewhere between 4 ¼ ” and 7” long, whereas a deer’s front track is between 1 ¼ “ and 4” long. Both have hooves that are heart shaped, and point in the direction of travel. Deer are more hindered by snow than moose, so finding a deer taking advantage of a moose’s trail by stepping directly in the moose’s tracks (see photo) makes perfect sense. (The moose’s foot was dragging as it stepped into the snow, thus causing the groove that leads to the track.)
Dramatic stories are not limited to the snowy woods of northern New England! This photograph was taken in Jamaica Plain, a neighborhood of Boston, Massachusetts. It tells the story of a small bird being killed by a relatively small bird of prey, most likely a Cooper’s Hawk or a Sharp-shinned Hawk – both are accipiters and predators of small birds (as well as other prey). Because their wingspans overlap, there’s no way to unequivocally state which of these raptors left this imprint, but whichever it was, it was successful, judging by the feathers and blood that remain. Both of these hawks are listed as Massachusetts Species of Special Concern, with the Sharp-shinned hawk sighted most often in the western part of the state. (Photograph by Sadie Richards)