Life with Three Feet of Snow

As you know, New Hampshire gets cold in the winter, sometimes very cold. It snows here, sometimes it snows very much. Animals that are native to the area, therefore, must develop strategies to survive the cold and to find food when everything is buried beneath three feet of snow, as it is now.

Many things simply hide themselves away in the warmest place they can find and wait it out. Insects, for the most part, are among those that simply wait for spring. As we've previously mentioned, lightning bugs may burrow as deeply as they can into the rough bark of trees for shelter. If we search carefully, we can find them there. Others take advantage of man's ability to control the environment. The Asian Lady Beetle and the Western Conifer Seed Bug may have burrowed into tree bark in their warmer native environments, but after migrating here to the much colder Northeast, they burrow into the cracks and crevices of the woodwork of our houses. Sometimes, they find a way all the way inside and we may find an active one or two inside the house in the dead of winter.

Some insects burrow into the ground and rely on the natural antifreeze compounds in their bodies to keep from turning into ice cubes. June Bug grubs, Japanese Beetle grubs and a number of others fall into this category.

Chipmunks hunker down in their burrows and truly hibernate through the winter. Chipmunks and some other rodents are known as obligate hibernators. That is to say they have a built-in need to hibernate seasonal regardless of whether there is still food available. Their body temperatures drop quite low, and body temperature and heart rate slow along with all their other metabolic processes.

Some animals, like the black bear, go into a more shallow form of hibernation when the weather gets cold and food becomes scarce. They also experience a drop in body temperature, but the drop is much smaller. They are less deeply asleep, and may even be roused during hibernation. While their hibernation differs from that of deep sleepers like chipmunks, they are still classified as hibernators.

Hibernation means that the animal in question suppresses its normal metabolism to much lower rates, enabling it to go long periods without the intake of food and to survive in harsh conditions. Some lower their metabolic rates more than others, but that is simply a matter of degrees within the spectrum of hibernation.

Other animals are still able to find food during the winter and remain active throughout the year. White-tailed deer, many birds, the gray squirrel, the snowshoe hare, and the coyote, for example, can be found roaming the woods and hills of New Hampshire even in the coldest of winters.

Some, particularly many species of birds, simply go away to where the weather is less severe. Migratory birds such as the Canada Goose and most warblers fit into this category. We've all heard of birds flying south for the winter, but it is less commonly known that for some birds that live even further north, the New Hampshire is a gentle enough winter climate for them to comfortably overwinter when compared to their breeding ranges. This means that during the winter months in New Hampshire, it is possible to find some species that are not commonly found here during the summer.

Some undertake a much lesser migration, remaining in the same latitude, but heading to more hospitable winter habitat. Many woodland ducks fall into this category. The Common Loon, Wood Duck, and Mallard Duck all fall into this category. Moving from the inlands ponds, lakes and rivers where they spend the warmer months to the seaside for the winter. They require open water in which to feed, so they head to the only open water that is guaranteed not to freeze in this climate, the ocean.

Even though we are in the very heart of winter, we can still find new species, even some that aren't here during the rest of the year.


 

Black Bear (Ursus americanus) Visits my Yard

Few animals that live in the New England woods cause as much fear as the black bear. Black bears

Black bear (Ursus americanus)
Photo by Brad Sylvester, all rights reserved.

are indeed dangerous animals and should be avoided, but a little knowledge and common sense is really all it takes to prevent a black bear attack. A few days ago, I happened to hear a noise outside and discovered evidence that a black bear had just been present.

The evidence included a bent steel trash can with teeth marks in the lid, and bear paw prints on the side of our chicken coop. The steel can contained chicken feed and the lid was secured by several straps which the bear was unable to remove to gain access. I was able to get the trailcam set up the next day and to get a few pictures, both with the trailcam and a regular camera (taken from the doorway, a considerable distance away).

Let me caution you that what I am writing here applies to black bears only, other species such as grizzly bears and polar bears are much more aggressive and do attack and kill humans with a much higher frequency. Black bears seldom attack people as prey. According to Mass. Wildlife, there have been about fifty cases of black bears killing humans in predatory attacks between 1900 and 2008. Of these, only 13 took place in the 48 lower United States. It does happen, but it's very rare.

Most black bear attacks happen when a bear is conditioned to expect food from humans. If the bear thinks you have food, it may be quite insistent in trying to acquire that food. This may involve coming very close and physically trying to take the food, bluff charges designed to scare you away from the food, or outright attacks. The New Hampshire Fish and Game Dept. cautions that a fed bear is a dead bear. Feeding a black bear is not a kindness, it is just setting the bear up for conflict with humans in the future, conflict that may result in a human injury, but most often results in the death of the bear.

Leaving bird feeders out in bear country once the snows melt is the most common way that people run into trouble with black bears. Black bears are omnivores, they'll eat almost anything from birdseed and garbage, to wild berries, small animals and carrion. They will also kill and eat chickens.

I have a chicken coop that is built to be bear-proof. While I don't doubt that a very insistent bear could get in if allowed to work on it for an extended period of time, it is made tough enough to discourage the bear and provide no quick rewards for his effort.

I bought this house in the woods because I like being surrounded by wild animals. I don't mind an occasional visit by a black bear, but I definitely do not want to encourage the bear to frequent my house or any other human habitation. That means making sure that everything that might provide the bear with a meal is securely locked away before dusk. We have hummingbird feeders that are brought inside each evening. I moved the chicken feed barrel to the inside of the garage, and I make sure the chicken coop is securely closed and locked by sunset each day.

The result is that the bear visited our yard for four nights in a row, but has only been back once in the two weeks since that initial string of visits. I can only hope the neighbors are being as cautious. I live near Little Blue Job Mountain which is covered in blueberry bushes. In the summer, the blueberry fields area strong attractant for black bears. Although I haven't seen them, I am told that if you visit the top of the mountain around 5:00 a.m. and clap your hands, as many as five or six bears will rear up from around the fields to see what made the noise. Once the blueberries come in July, I don't expect we'll see any hungry bears searching for food in our yard.

Meanwhile, when going out into the yard at or after dusk, I check for bears and make some noise to alert any that might be unseen to my presence. According to one study, black bear attacks occur most frequently when a human shows fear or weakness by such actions as running away. Prey runs away. If you run from the bear, the bear knows that it has nothing to fear from you and can attack with impunity. The second most likely circumstance for a bear attack is when a human behaves with indifference toward a bear's presence, just going about one's business as if the bear weren't there. In my opinion, this causes anxiety to the bear. You're not afraid of it, so you might be dangerous, but you're not attacking so perhaps an aggressive tack by the bear might drive you away. If you are acting indifferent to the bear, you may turn your back to it or present some other opportunity for it to take you by surprise.

The fewest black bear attacks occurred when the human took an aggressive stance. Never turn your back on the bear. Face it, back away slowly and carefully. Stay in a group, if possible. Black bears will often try to gauge your strength by pretending that it is going to attack and seeing if you bolt and run. A loud snort may precede a bluff charge. If you turn and run, you'll invite attack. Instead, stand your ground, try to appear as big as possible by raising your arms over your head, yell, and have any weapon you can find handy- a stick, a rock, a camera tripod, or anything you can use to strike the bear. If the bear does initiate an attack, hit it as hard as you can as many times as you can. Fight furiously to demonstrate that the bear will risk pain and injury if it continues to attack. Keep fighting for as long as it takes. Black bears don't often stop attacking when an adversary plays dead. Your odds are better fighting back.

Of course, that's a last resort, the bear is much more dangerous than you. Avoiding conflict is always the best course of action. When walking in places where there may be bears, make noise so any nearby bears will not be surprised. If you see a bear, do not approach it or turn your back. If a bear is near a dead animal upon which it has been feeding, it may actively defend the area. Give a very wide berth to any bear that doesn't immediately flee. Pay attention to the bear's body language. Often you can tell if an animal is agitated. Increasing the distance between you and the bear generally helps calm it while getting closer increases its alarm.

Most black bears will avoid human presence. The exception is when there is food in the area. This can be carrion, berry bushes, the smell of hamburgers cooked on your campfire, the sandwich in your backpack, or the bird feeder on your deck. Black bears are generally calm creatures, but they really don't like it when food is taken away from them or they are prevented from getting to food they know is present.

Quick Facts about the Black Bear (Ursus americanus)

Where do black bears live? According to National Geographic, black bears might travel a range of 25-80 square miles, which may well overlap with the territories of other black bears.

When is it here? Black bears are here all year round, although they will usually stay in their dens in a strong winter torpor. Despite popular opinion, black bears do not hibernate as deeply as some animals and may wake if disturbed during the winter. They may lose a quarter of their body weight during the winter and are quite hungry when they emerge in the spring, often searching out easy meals like bird feeders.

Life Cycle: A black bear will usually have two to three cubs which are born in the winter den. As the mother bear languishes in winter torpor, she will nurse the cubs until the snows melt and it warms enough to leave the den. The cubs will stay under the close protection of the mother bear for about two years.

What is the lifespan of a black bear? National Geographic says the average lifespan of a black bear in the wild is 20 years, but the average may be considerably less in areas where they are actively hunted.

How big do black bears get? Although they can get as heavy as 600 pounds, that is an exceptionally large bear, especially for New England. A very large adult here may be about 400 pounds with 250 pounds being the more common upper limit for an adult male in New Hampshire. Females may be half the size of a male. Adult black bears are about five to six feet in length (nose to tail). Black bears may be about three feet tall from the ground, but can rear up on their hind legs to more than double this height, especially to reach food like a bird feeder hanging from the eaves of a house. Bird feeders above eight feet high are generally safe from a bear, although the bear can smell birdseed from a mile away and may be attracted to the area even if it can't reach the feeder. Spilled seed on the ground may be enough to keep it coming back night after night.

What do black bears eat? The short answer is almost anything. The long answer is insects (including wasps and bees), small animals, grasses, berries, fruit, seeds, most human food, garbage, carrion, honey, and pet food.

Appearance: A black bear's coat is generally black, but may be a very dark brown. A black bear may or may not have a white patch on the underside of its chest. The muzzle tends toward brown regardless of the bear's main coloration. Black bears blend into shadow very well and are extremely difficult to spot in the dark, especially if they are holding still.

What do bear tracks look like? Black bears have five toes with non-retractable claws. (See the photos below.) The rear foot is longer and almost human shaped. An adult hind foot print may be roughly eight inches long, give or take. The front footprint is shorter, lacking a defined heel and may be 4-5 inches in length. Bear feet are wide, about five inches from side to side. Depending upon the type of ground, claw marks may be present in front of each toe. In soft dirt or dust, fur marks may be visible around the outline of the foot.

 

Bear prints indicated by black arrows. Raccoon and coyote

prints are also evident on the side of our chicken coop.

Photo by Brad Sylvester, all rights reserved.

Bear track in dried mud about two miles away from my yard.

Photo by Brad Sylvester, all rights reserved.

 

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Hole in the ground becomes winter den

This hole goes as deep as I can see, twisting around
underground boulders. Now it appears that porcupines are
using it for a winter den.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

During the summer, I found a deep hole in the ground in my backyard forest. It's right at the base of a tree and if you peer into it, you can see about six feet down although there are numerous very large stones (two foot diameter or more) causing the hole to twist and turn as it descends. It seems to go much deeper. At any rate, it's well below the frost line for New England which is somewhere just under three feet as I recall from my study of architecture in high school.

Two days ago, we had about three inches of snow and I happened to walk through the part of my yard where the hole is. There was a very well-trod path coming out of the hole and proceeding about 15 feet to another similar, but smaller hole, in the ground. From there, the path continued on and split. One fork went to the base of a nearby pine tree, straight to the trunk. From the tree, it appeared as though it came straight away from the trunk and continued into the forest.

The tracks seemed to show that the path went up the tree and came back down before continuing. The paths were very well traveled as I mentioned. So, it was impossible to make out individual prints to see what creature or creatures had made the trail. There was no scat or other evidence to help determine what might be using the dens.

Today, I went back to install my trail cam in a position to catch photographs of whatever it is. There was new evidence. Urine and scat right outside the holes in the ground suggested that it might, indeed, be what I suspected. A communal den of a fairly common New England mammal that does not hibernate in the winter: the porcupine.

Communal Porcupine Dens

Second suspected porcupine den located just 15 feet from
the previous one. One trail leads to the other opening,
and one leads further into the forest.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

Porcupines generally have solitary or family dens, but in periods of severe winter weather, they may group together in a single den which benefits them all by the sharing of the communal body heat. I believe these two holes in the ground are communal porcupine dens. Today, I placed my trail cam in a position where it will almost certainly get some good identification photos of whatever is spending its days in these holes.

Which brings us to the question of why don't porcupines hibernate or go into a winter torpor like so many other small mammals. I would guess that it has to do with the preferred diet of porcupines. They eat the small, tender twigs of evergreen trees, green bark, and the young evergreen needles. They especially like hemlock. Of course, as the name says, evergreen trees stay green and full of porcupine nutrition throughout the winter. There is no need, therefore, for a porcupine to shut down its metabolism and wait for the new growth of spring. They will also eat fallen fruit when it is available.

Signs of Porcupines

As an aside, there are two sure signs of porcupines. First, lots of bits of the ends of hemlock branches littering the forest floor under the tree. The porcupine climbs out on the branches to eat the small twigs and to reach the newest needle growth. It eats the needles from the small twigs, but as it does so, the branch tips are discarded and fall to the ground. Porcupines, being both lazy and creatures of habit, will revisit the same few trees over and over again around its den, relying on the growth of those trees, especially during the spring and summer months to keep the porcupine's plate full.

Porcupine Droppings
The second sure sign of porcupines, is an excess of droppings outside of a ground level tree hollow, small cave or other suitable den entrance. Porcupine's are not meticulous about the placement of their droppings. Very large piles of droppings of varying ages will, therefore, accumulate outside the entrance to a porcupine's den over time. As they walk through it several times a day, trailing their dragging tails and quills, they will form a stained trail into and out of the den. On the positive side, the scat is made up almost entirely of undigested cellulose lacking in strong odor. Procupine droppings are a bit like rounded, oblong deer droppings, but tend to have a pronounced curve, making them almost "C" shaped. Other than outside the den where they accumulate, they'll be present in much smaller piles than deer droppings, or even individual pellets.

A trail leading straight into a tree trunk and then away
indicates an animal that climbed up the trunk such as
a squirrel or porcupine. These tracks are too big for
a squirrel.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

Porcupine Winter Behavior

As long as a porcupine can withstand the cold temperatures or winter, they can find plenty of food to sustain them even in the deepest snows of winter. By grouping together during the coldest weather body heat of many porcupines is combined to raise the ambient temperature of a den, which may be underground or in a large tree hollow. Together they can keep the temperature in the den much higher than any individual could by itself. That means fewer calories need to be burned to stay warm. In extreme conditions, it means the difference between surviving and freezing to death.

Of course, when it comes to the "whys" of animal behavior, we can only make assumptions based on the available evidence. There may be some other reason for communal dens during the harshest part of the winter, but Occam's Razor says that we should first assume the simplest explanation is correct until additional evidence disproves it.

I'm actually very excited to find dens of any mammal in my yard because it offers the possibility of regular and close observation of the den's occupants to learn more about their behavior than I might learn by simply catching pictures of them visiting feeding stations or walking along a common game trail.

Hopefully, one or more of the porcupines, assuming I am right in my guess of the occupants of these dens, will choose to raise offspring here in the spring. That opens up the possibility of me putting a remote camera inside the dens in addition to a camera outside the den to observe the kits as they develop.

I can hardly wait.

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Update: My new YouTube channel: @WhatLivesinmyYard talks about the porcupine in Episode 1.

Snow Tracks of the Striped Skunk (Mephitis mephitis)

To paraphrase Robert Frost:
"Whose tracks are these?
I think I know.
It is the striped skunk,
The odor tells me so."

With the overnight snow a couple of days ago, I awoke to find meandering trails throughout the back yard where some creature had wandered all over the back lawn. The snow was wet and melting, so no distinct footprints could be discerned, but there is still enough evidence to identify the trail-maker.

The meandering route would be typical of a striped skunk (Mephitis mephitis) searching for grubs under the roots of the grass. Additionally, a couple of weeks ago, there was a very strong skunk odor out by the sun porch. It must have sprayed either under the porch or right next to it. The odor was literally strong enough to make a person sick until we aired it out the next morning. This evidence is enough to identify the striped skunk as the largest wild animal identified so far in this blog as a resident of my yard.

It leads me to wonder though: did the skunk run into some other creature living under the deck and use its defensive spray? It seems odd that it would find an occupied spot and then choose to live there. I suspect, however, that the skunk, out looking for a home used its musk to claim the spot. Any other animals in the area would be able to smell the skunk's spray for months, giving them a very good reason not to go near the skunk's winter den. I've never heard of this sort of behavior, but, logically, it makes sense to me. I'll have to do some further research.

I suspect the striped skunk has taken up residence beneath our house. It's odd to see its tracks in the snow, because skunks have usually gone into a winter torpor before snow sticks on the ground, as that doesn't often happen until the ground is frozen at the surface level, but this one is still actively hunting in the early snow. Young skunks often have a tough time surviving their first winter (see the Quick Facts below), so I'll be interested to see if it is still around in the spring.

Skunks can wreak havoc on a well-maintained lawn as they root for grubs. They will wander around the yard, digging little holes sporadically as they locate grubs. They'll also eat insects on the surface as they find them. Earthworms or beetles caught above ground make a nice addition to the skunk's diet. They also hunt larger prey such as mice, moles and frogs. They'll eat bird's eggs and berries and grains, as well. In an urban setting, bird feeders and garbage cans make attractive feeding stations for skunks if they are left within reach. Skunks are small and are generally unable to knock over a medium weight garbage can, but if bags of garbage are left out, they'll happily tear into them.

Skunks hunt at dusk and dawn and may sometimes be seen in the early morning hours as they finish up their feeding and head back to their dens for the day or during the evening hours caught in the headlights as one drives along country roads. Animals that are active at these times are referred to as neither diurnal nor nocturnal, but crepuscular.

Skunks and Rabies:

Skunks are one of the most common vectors of rabies in North America and should always be given a very wide berth for that reason if not for the smell. Skunks that act aggressively toward humans should be reported to state wildlife agencies, especially if there is an active outbreak of rabies in the area.

Skunk Spray

William Wood of Humboldt State University offers a chemical analysis of skunk spray. Thiols, he says, are responsible for the strong odor and can be chemically nullified with hydrogen peroxide or baking soda. Interesting, he notes that a second class of thioacetates found in skunk spray doesn't smell as strongly, but when later mixed with water, they may change into more odoriferous compounds. I would think that this might be useful for marking territory as it would linger and be refreshed whenever it was damp outside, although I still haven't found any information suggesting that skunks use their spray for this purpose.

Quick Facts about The Striped Skunk (Mephitis mephitis):

What do striped skunks eat?

Striped skunks are opportunistic omnivores. They'll eat a wide variety of insects, small mammals, reptiles, fruits and berries, grains and seed, and occasionally carrion.

Where do striped skunks live?

Striped skunks live throughout North America where they are widespread and common throughout Canada, the United States, and northern Mexico. In terms of habitat, skunks are fairly adaptable and have probably benefited from the conversion of so much landscape to short-cut lawns which make excellent foraging grounds for them. They are also found in forests and agricultural lands as well.

Where do  striped skunks go in the winter?

Striped skunks do not migrate. In the winter they don't truly hibernate, but fall into a state of lower metabolism and reduced activity. Food is hard to find once the ground freezes and the skunk's prey holes up for the winter, so skunks compensate by fattening up as winter approaches and then relying on the reduced needs of their lower metabolism to see them through until spring. The state of reduced activity is called a winter torpor and although the skunk will sleep quite a lot during this time, it does have periods of wakefulness unlike a true hibernation.

What is the lifespan of the striped skunk?

Skunks generally live 2-4 years in the wild, up to 15 years in captivity.

Life cycle of:

Skunks do not mate for life, or even for a single year. Males are opportunistic breeders and will mate with any fertile female they find and then move on. Females raise and care for the young for their first summer until they are old enough to find their own food and go their separate ways. Litters range from 4-7 kits says the University of Delaware's Emily Magnani, and typically live from 2-4 years in the wild. Magnani says that as many as 90% of skunks do not survive their first winter.

Notes:

Despite their poor first year survival rate, striped skunks are common and area species of least concern according to the IUCN Red List of Threatened Species. Once widely harvested for their distinctive fur, they have, fortunately for the striped skunk, fallen out of fashion. Skunks fall prey to the usual suspects, coyotes, wolves, bobcats and the like. They'll also fall victim to dogs although once the dog gets a faceful of skunk fury in the form of its defensive spray, the fight usually ends with the dog running home.

I'll try to get some pictures with the trail cam to add to this post, but with bad weather expected and winter approaching, it may take some time.