Porcupines - Fact and Fiction
Recently, I was talking to a friend, who mentioned that he had seen on television that when determining the sex of a new born porcupine, it is necessary to have a DNA test done on a quill. Now, I had never heard of this, and after doing some research, I found that my friend’s information was correct.
The following is what the Smithsonian found: “When born porcupine quills will soon become hard. Because prehensile-tailed porcupines don't have external sex organs—making it difficult to tell if they are male or female as babies—our geneticists use the DNA in a quill to determine if a porcupette is a male or female.
Figuring out the sex of a porcupine can be a difficult task. Porcupetts aren't always easy to handle, and when young they show no sexual dimorphism. However, veterinarians, geneticists, and keepers at the Smithsonian's National Zoo have figured out a novel and easy way to determine the sex of prehensile-tailed porcupines, and all it takes is a single quill.”
When we moved to Bradford County in 1969, the only area where I saw porcupines was on Barclay and Armenia Mountains. Today, the porcupine population is high, and their range has expanded. It is not uncommon to see road-killed porcupines in most sections of the county. The Pennsylvania Game Commission has re-introduced the fisher in an effort to reduce the porcupine population.
A porcupine is one of our easiest recognized animals. Through the generations many fables have been told about the porcupine and here are a few: a porcupine can throw its quills; a female porcupine does not breast feed its young; a porcupine is born without quills; a porcupine is protected by law because it is assumed a person lost in the woods can easily catch and kill a porcupine. ALL OF THESE STATEMENTS ARE FALSE.
In the fall, I would often receive a call from someone that wanted me to identify a sound he or she had heard in the woods. The sound was described as a loud shrieking call followed by another animal calling from a distance away. The calls continued; however, they were becoming closer to each other. Finally, it appeared as if the two animals met up with each other. The caller always commented that the sounds were extremely eerie.
These calls were made by male and female porcupines as part of their mating ritual. Usually, porcupines are silent animals; however, during the breeding season (September through November), they grunt, groan, shriek, bark and whine to attract each other. These calls are often heard up to one quarter of a mile away.
When two porcupines meet they face each other, rub noses, gnash their teeth, stand on hind legs and scream at one another. Body movements, which could appear as if the two were dancing, are performed. Before mating, the male showers the female with urine. Unlike many mammals, the males do not fight over females.
The gestation period is 205-217 days, which is longer than the period for white-tail deer. Almost seven months after breeding, the female will give birth to one young called a porcupette. April, May and June are the months when the young are born, with this wide variation due to the breeding season being so long in the fall. Although there is a long breeding season, it is reported that up to one half of all adult females can go unmated in any given year.
Due to the long gestation period, the young porcupine is one of the largest animals at birth in comparison to the mother’s body. At birth, a young porcupette, which will weigh about one pound and measure approximately twelve inches in length, has eyes open, incisor teeth well developed and is fully furred and quilled. The quills are about one quarter of an inch long, soft and flexible and will dry within the hour, at which time the young porcupette is able to defend itself.
A few days after being born a young porcupette can climb a tree and also eat the bark and cambium layers of a tree. The female will continue to nurse the young for several weeks; however, the mother and young will have separated by fall.
Our porcupine is known as the Canadian porcupine because it inhabits large areas of northern North America, including Canada. The porcupine belongs to the Rodentia family, which also includes mice, squirrels, beaver, etc. The name porcupine comes from two Latin words, porcus, meaning swine, and spina, meaning thorn. The scientific name is Erethizon dorsatum, which means "the irritable back.”
A porcupine can weigh nine to 20 pounds. It is covered with 30 to 35 thousand quills over its body, except for face and stomach. The length of these quills, which are between one to four inches in length, vary as to the part of the body they grow.
The quills are highly polished. Each quill has a barb similar to a fish hook that causes its removal to be quite painful. If a quill is lodged in the flesh, the actions of the victim’s muscles engage the barb, drawing the quill inward as much as an inch a day. This can become fatal as the quills pierce vital organs. If a porcupine loses a quill, replacement growth will begin within two days. This new quill grows at a rate of one half millimeter per day, and the growth can continue for two to eight months. When fully developed there will be a closure at the base of the quill so that no bleeding occurs when the porcupine uses the new quill.
And under all those quills, the porcupine has stiff hair
When a porcupine is not alarmed its quills will lay flat on its back; however, once danger is detected, the quills stand erect, and the porcupine immediately turns its back on approaching danger. The tail, which is between six to eight inches long, is the business end and always kept towards danger. Porcupines cannot throw their quills; however, if a person were to reach down to touch the animal, the tail would be flailed and the intruder would end up with 12 -15 quills in the hand.
The porcupine walks flat-footed, with a top speed of about two miles per hour, which is the reason that many are hit by vehicles.
A porcupine’s front and back feet have long curved claws that are used for climbing trees. The back feet have broad soles covered with small bumps that also lend traction when climbing trees.
The porcupine has four large incisor teeth for cutting and gnawing. These incisor teeth are always growing; however, the porcupine’s diet keeps wearing the incisor’s down. The large incisor teeth enable the porcupine to eat aluminum signs, cans, plastic, salt, grease, soap, and glue in plywood, pressure treated wood, animal bones and deer antlers. In one night, a porcupine can eat one pound of food.
Just What Makes that Ant?
While working in the garden, I stooped to pick up a bag of mulch, which had been laying there for a few weeks, and noticed hundreds of ants, scrambling about to pick up their eggs and carry them underground to safety. I quickly got my camera out of the truck and took some pictures. Later, I went to the computer to identify the ants.
According to a publication from the Penn State Entomology Department, the ants were the typical pavement ants. These ants are an introduced species and one of the most commonly encountered house-infesting ants in Pennsylvania. The pavement ants were likely carried to the United States in the holds of merchant vessels during the 1700s to 1800s. These ships were filled in Europe with soil to provide ballast on the trip to America. Once in port the soil was removed, and the ships were loaded with goods to take back to Europe.
The pavement ant is a soil-nesting specie that currently has a distribution from New England to the Midwest; south through the Mid-Atlantic States to Tennessee; parts of California and Washington.
Winged reproductive ants typically swarm in the spring but have been known to emerge from heated structures throughout the year. It is not uncommon to see these ants swarming in late fall and during February in colder climates.
The ants mate after emerging. The queens, of which there are many, burrow into the soil to begin laying eggs. Worker ants develop over a two-to-three-month period. Homeowners become aware of these ants as they mine the sand and soil from under concrete slabs, patios, sidewalks, driveways, and basements. These ants are often referred to as mason ants due to their nesting behavior of moving the dirt.
The pavement ants are one size in a colony. They do possess stingers; however, a person will not be stung unless resting an arm or leg over an infested area.
Pavement ants feed on a wide variety of food, including sugar, nectar, fruits, and syrups; grease, dead insects, and small seeds are collected and stored in the nest. Most morsels of food that fall to the floor will be consumed.
Ants are common insects, with some unique capabilities. More than 12,000 known ant species occur worldwide. In tropical forests, the ant population could be half of all the insects living in some locations.
Perhaps some of you remember this song recorded by Frank Sinatra.
Just what makes that little old ant
Think he'll move that rubber tree plant
Anyone knows an ant can't move a rubber tree plant
But he's got high hopes, he's got high hopes
He's got high apple pie, in the sky hopes
So any time you’re gettin' low
'Stead of lettin' go
Just remember that ant
Oops! There goes another rubber tree plant.
Ants have amazing strength, with the ability to carry up to 50 times their own weight. In comparison, a second grader would be able to pick up a car.
The following are amazing facts about ants: some queen ants could live for many years and lay millions of eggs; ants do not have ears, with hearing made possible by feeling vibrations in the ground through their feet; usually, when ants fight, it is to death; foraging ants leave a pheromone trail so they know where they’ve been; queen ants have wings that are shed when a new nest is begun; ants have no lungs, with oxygen entering and carbon dioxide leaving through tiny the holes of their bodies.
The colony only survives a few months after the queen dies, since queens are rarely replaced, and the workers are unable to reproduce.
There are three kinds of ants in a colony: queens, female workers, and males. The queen and the males have wings, while the workers have none. The queen is the only ant able to lay eggs. The male’s job is to mate with future queen ants. Males have a short life after mating. Once the queen grows to adulthood the remainder of her life is spent laying eggs. A colony could have one queen or many queens, depending on the species.
Ant colonies also have soldier ants, with the job of protecting the queen; defending the colony; gathering or killing food, and attacking enemy colonies searching for nesting space. When another ant colony is defeated, the eggs are taken. After the eggs hatch, the new ants become the "slave" ants for the colony.
If payment ants enter into your home, they can be controlled and the colony eliminated through the use of baits that workers carry back to the nest. Many different types of bait are available to the homeowner in this regard. However, baits containing boric acid are slower acting and do not kill the workers before they have had a chance to share the bait with the queen and developing immature ants. Place the baits in areas where ant activity has been observed and make certain that neither children nor pets can reach them. Maintain a sufficient amount of baits to satisfy the colony by replacing used baits. Baiting can require two weeks or longer obtaining control.
Snow Fleas
Have you ever taken a pleasant hike in the summer and autumn woods only to be pestered by annoying insects? By the time winter arrives, insects are smart enough to seek a warm place to sleep through the cold months. This rule is followed by 99.9% of all insects.
During the dead of winter, on a sunny day, there is an insect sometimes noticed on the surface of the snow. Snow fleas, which are neither fleas nor true insects, are more commonly known as springtails. Springtails are actually anthropoids called collembola, which comes from two Greek words: coil, meaning glue and embol, meaning a wedge. Both words come from the springtail’s ability to adhere to the underside of a leaf.
Springtails are primitive in that they do not possess normal insect legs, eyes or mouthparts. They are wingless and have simple eyes that only detect light or dark, while most insects have compound eyes. Snow fleas possess very unusual mouthparts that are contained inside the head rather than protruding on the outside like other insects. They have a very simple metamorphosis, going from eggs to nymphs to adults. However, what sets them most apart from other insects is their quirky method of locomotion. Although a springtail lacks wings, it has the ability to catapult itself by releasing two tail-like spring projections (furcula) on its abdomen. A springtail can fling itself over one hundred times its body length. In one study, it was found that the distance of springtail propulsion was found to be up to 12 inches. This is quite a feat since the snow flea is approximately 3mm long, which is the size of the period at the end of this sentence. The study concluded that springtails have neither control over the direction or distance of their flight, nor do they have a way to steer once airborne. After releasing the spring-loaded tail, the springtail is sent flying through the air without ability to control the direction of flight. Frequently, the springtail lands in the same spot or a small distance away.
Snow fleas are black and appear as pepper sprinkled on the snow. During the winter months when warmth from the sun heats the air, the snow fleas climb up through the snow to congregate on top of the snow, usually at the base of a tree, where it is slightly warmer.
A tree collects and releases the sun’s heat, causing the snow at the tree’s base to melt. These areas are known as microclimates (a small area with a different climate than the surrounding area).
Snow fleas can be easily seen on the snow, often at the base of a tree where it is slightly warmer
Although snow fleas are active throughout the year, they are more noticeable during the winter months when their black bodies show against the snowy background. To find snow fleas during the summer months, one must look closely at leaf litter, where they can be found hanging to the underside of leaves.
After mating in the spring, the female lays her eggs in the soil. The emerging nymphs undergo several molts. By the time winter arrives, they are the size of an adult.
During the summer and fall months, they live in the soil, feeding on decaying organic materials, bacteria, fungi, algae and pollen. They eat everything (including their own droppings) or nothing at all. In one laboratory study, it was found that springtails had gone without eating for up to four years.
There are over 6,000 known species of springtails. They are so adaptable that almost nothing man does will bother them. Springtails have been found in Hawaiian volcanoes and in the Antarctic.
The springtails can be active during a cold winter due to an antifreeze-like protein that is produced in their bodies. Scientists have found these proteins to be glycine rich and unlike any known proteins. There are hopes that creating similar proteins will be helpful for preventing the formation of ice crystals in the tissues of stored transplant organs. This would allow organs to be stored at lower temperatures, increasing their lifespan outside of a living body. Unlike other proteins, the proteins found in snow fleas break down easily at higher temperatures.
Since snow fleas do not have organs for breathing they must receive oxygen directly through their skin, which needs to be moist for an oxygen exchange to occur. This is why snow fleas need to stay in damp places, such as a sunny spot where the snow is beginning to melt.
When preparing to migrate millions of snow fleas can be seen on the surface of snow. Although this migration could only be a short distance, it could take several days due to their resting at night. Migrations take place when the food supply has been exhausted.
Thoreau wrote this about the tiny snow fleas, “A creature whose summer and prime of life is a thaw in winter.”
Larger insects feed upon the snow fleas, and in turn, these larger insects are eaten by birds, which are fed upon by larger predators. The little snow fleas are part of the food chain; however, they are also part of nature’s cleanup crew that cleans up the forest leaves that are turned back to soil.
More on Stones
Have you ever heard of a person collecting ordinary stones? It sounds strange but my wife, Mary Alice, collects stones (I don’t mean diamonds) from areas that we visit. When back home she finds a home for the stones in the flower gardens and along the driveway. We knew a lady that lived in Monroeton that always talked about her rock garden. We stopped by one day and saw that she had a genuine rock garden, where there were no flowers only stones. In the future, geologists will be surely puzzled when rocks from one part of our country are found many miles away.
However, the transporting of stones is not new. Over 300 years ago, Native Americans transported stones up and down the East Coast. In Pennsylvania, we have a stone known as jasper that the Native Americans mined from pits near the present town of Vera Cruz, which is located south of Allentown. More than 100 jasper pits have been discovered in that area. Jasper is a type of quartz in shades of red, yellow and brown. The Native Americans found this stone ideal for making arrow heads, spear tips and axes.
After reading about jasper, I began to wonder if there is a difference between a rock and a stone. Webster’s dictionary defines a rock as a large outstanding natural mass of stone; a natural mass of one or more minerals, consolidated or loose. Our word rock is believed to go back to the old French word rocque, meaning stone. Our word stone comes from the Germanic word stein, meaning stiffness or solidity and also the source of the Greek word stia, meaning pebble. Webster’s dictionary defines a stone as a detached piece of rock.
Geologists study rocks to learn about the earth’s past. Fossils are found with the remains of the durable parts of a plant or animal that lived on earth millions of years ago. Fossils have also been found with an imprint of a foot of an animal, such as a dinosaur.
Fossils, which are usually found in sedimentary rocks, are a type of rock that makes up three-quarters of the land surface of the earth. Charlie Fox, a retired earth science teacher, is responsible for my interest in looking for and collecting fossils. Fossils are fairly abundant in Bradford County. Here, in our county, we have many stone walls that were erected by early farmers while clearing their fields. Stones from these walls have revealed many trilobites.
Mother Nature has also transported rocks from one area to another.
The Appalachian Mountains that run through Pennsylvania have an interesting history. The Appalachians, which are ancient mountains that were as lofty and mighty as the present Rocky Mountains; however, they have been worn down by wind and water. During what is known as the Permian Period, the Appalachians were born as the earth had a great folding; causing the great basin that covered most of Pennsylvania to be lifted to a great height. However, erosion attacked the mountains, and they soon became a flat featureless plain, which stood only a few scores of feet above sea level.
Then, another force began to operate on the Appalachians. This time, instead of being folded, the area was lifted vertically. The higher the mountains were lifted, the more the streams and rivers gnawed at the rocks.
The Susquehanna and Delaware Rivers cut passes through the mountains known as water gaps. If traveling on Route 15 south from Sunbury to Harrisburg, you are going through a water gap. When looking at the mountains on both sides of the river, you’ll notice that they are the same height. If the river is low, rows of rocks that run from one mountain to the other are visible, allowing us to see how the mountains were eroded by the river. Also visible are the rocks that stand almost vertically, most often seen where the highway department cut through the mountains to build the highway.
The last period to attack the Appalachians was the Pleistocene Epoch (Ice Age). The last two advances of the ice glaciers entered into Northern Pennsylvania, pushing rocks and stones ahead. Each time the glaciers retreated, the melting ice deposited a mantle of rocks that was picked up and deposited hundreds of miles away. Along with many different varieties and sizes of rocks, these glacial deposits also contained clay and sand.
The North Central part of the state, including Bradford County and into Northeastern Pennsylvania, is known as the Allegheny Plateau. This plateau is a highland that has been eroded by streams, which created deep valleys and a hilly topography. This area has many lakes, swamps, peat bogs and extensive deposits of loose sediments. Unlike the rocks in the mountains to our south, the rocks in this area are primarily laying horizontally because these rolling hills were formed by the water of the receding glaciers. Since moving water has a tendency to separate things, gravel banks will produce items of the same size.
On your next venture into the mountains and hills of Pennsylvania, a very interesting story can be seen if you take the time to look closely at the rocks and mountains.
Stone Walls
The first thing I do when beginning a day of deer hunting is to search for an old stone wall surrounded by forest to take up my stand. Then, I take a few stones from the wall and place them in front of a tree, and now, I have a seat and a backrest.
While on deer stand, I have an opportunity to check out my surroundings. The stone wall seems to stretch endlessly through the woods, making it hard to imagine that the area had once been a cleared field.
My mind wanders back to the hard labor that went into building this stone wall. The cutting of trees and pulling out the stumps and roots would have been a giant task; however, this was only half of the work. The stones were gathered and piled on a stone boat, which was pulled by either horses or mules to the far end of a clearing. Next, the stones were unloaded and stacked. Since fencing materials were either scarce or non-existent, the farmers also used tree stumps, with the connected root systems, to build fences. Although gathering stones was hard work, they were free; therefore they were used in building houses and barn foundations.
An old saying goes, “Good fences make good neighbors.” However, I doubt that the early farmers gave any thought to this saying. Fences were built to keep the livestock out of the fields. Here, in Northern Pennsylvania, the rocky soil yielded an abundant supply of fencing materials. Every time the farmer plowed his field, he unearthed a new supply of stones that needed to be removed. Each spring the stone walls were piled higher and extended further.
Today, the condition of stone walls can tell you something about the men that built them. Many stone fences that were neatly stacked are still standing; however, if a stone wall appears to have caved in, perhaps the farmer took shortcuts and simply chose to throw the stones on a pile.
One does not have to travel far to see that stone walls were built of different types of stone. For example, in Southern Pennsylvania, the walls were made from limestone; however, here in Northern Pennsylvania, Devonian red shale is found in our walls, and if you travel to the New England area, you will find the stone walls contain a great amount of granite.
Scientists believe that different types of stone were formed when the earth was a mass of molten material. Within this molten mass, the heavier elements (iron, nickel, etc.) sank deep below the surface; while the lighter elements floated on top. As the liquid mass slowly cooled, the elements tended to draw together. Over most of the earth’s original crust, many crystals took the form of granite. Under this thin layer of granite were molten rocks. As the molten rocks cooled and contracted, great pressure forced the land up to form mountains, and in some places, huge cracks opened; molten rock flowed upward, spreading out over the layer of granite; smaller cracks were filled with this molten material to form veins of rocks, and then boiling water carried the elements in a solution from the inner earth and repositioned in the cracks. This is how some parts of the earth’s surface became rich with concentrations of rare minerals that came from the deep interior of the earth.
Later, the forces of nature (water, wind and ice glaciers) spread these minerals over the surface of the earth; however, the soil usually draws most of its mineral content from the underlying rock. When the rock is rich in important minerals (example, limestone) the soil usually provides a rich environment for life; while rocks (example, granite) offer little mineral food and provide little nourishment for plants.
The stone walls created by early farmers have provided a special habitat for small animals, such as chipmunks, mice, weasels, rabbits, reptiles (snakes, etc.), which attract larger animals, such as foxes, coyotes and a host of other predators. Years ago contractors were buying these stone walls from land owners. The stones were removed and placed on pallets to be shipped to other areas, where the stones were used in construction and landscaping. If I remember correctly, the landowner received $25 a pallet, while the contractor sold the pallets of stones for approximately $250, which did not include the shipping paid by the buyer.
Stump fences were built from the tree stumps pulled out of the ground by oxen or horses, with a device known as a stump puller. This was a very dangerous job. After the stump was pulled from the ground, it was dragged to the end of the clearing to be used as a fence. Today, these stumps are being sold and used in landscaping,
I believe that tearing down our stone walls is destroying a part of our heritage, along with city planners that are razing our old buildings to replace with parking lots and buildings that have neither eye appeal nor charm. However, many local groups have organized in an effort to save these old buildings as historical landmarks. I strongly feel that we should be doing the same with the stone walls and stump fences.
As a Robin Cocks it’s Head
We spent Christmas with our son and his wife and their family, who live in Arlington, Virginia. On Christmas Day, the temperature was in the low seventies, with scattered showers throughout the day. We watched as robins hopped about on their lawn, pausing and cocking their heads to the side while searching for a worm. Have you ever wondered if the robin is listening for a worm or looking for a worm? Well, the answer is that the robin cocks its head to focus its eye on the worm; however, at the same time, the bird is also listening for danger lurking nearby.
According to the Encyclopedia of North American Birds, a bird has two eyelids (folds of skin), one above the eye and one below. Birds that are active in the daytime draw up the lower lid when closing their eyes; whereas, birds that are active at night have a more active upper lid when closing their eyes.
Birds also have a nictitating membrane (aka third eyelid), which can be drawn across the eye from the lower nasal position upward and rearward to moisten and clean the cornea.
Birds have a highly developed sense of sight. Man’s vision is about equal to a bird’s sight; however, birds have faster vision, which allows quickness in picking up details.
Usually, the eyes are the largest part of the bird’s head and often weigh more than the bird’s brain. The ostrich has the largest eyes of all birds. When looking at a bird’s eye, one sees only a small part of the eye because the largest part is hidden by the lids and skull.
The eyes of a bird are fixed in the sockets, which means that a bird must turn its head and neck to gaze in a different direction. All birds have monocular (one-eyed) vision, which allows for seeing independently with each eye, and binocular vision, which allows for looking straight ahead.
Most songbirds have a smaller range of monocular (side) vision and cannot see behind without turning their heads; however, the American woodcock, with its eyes placed toward the top of its head, can see backward, forward, upward and downward at almost 180 degrees with each eye.
The bittern usually lives among reeds and often escapes notice by standing very still, with its head pointed skyward. The bittern’s eyes are placed low on the head so that the bird can still look forward binocularly, while maintaining this pose.
Birds that feed on small objects, such as seeds and insects, must be able to see them sharply and clearly; therefore, their eyes are rich in cones and adapted to daytime seeing. Other birds, such as owls that must be able to see at night, have eyes that are rich in rods; however, owls also have enough cones so that they can see sharply during the day. Birds can see colors as well as man.
Hearing ranks next to sight in its importance to birds and their survival. The ear openings of most birds are hidden under feathers at the sides of their heads, just below and in back of the eyes. The feathers covering the ears do not interfere with a bird’s hearing. Special feathers in front of the ears are adapted to minimize turbulence in flight and help to protect the hearing organs. There are no fleshy and cartilaginous outer ears that catch sound waves as in man and other mammals; however, an owl has a moveable skin fold, which is most prominent along the front edge of the ears, that reflects sounds that come to the owl from behind. Also, in owls, the facial feathers help to detect sounds.
Owls hear very well because their right and left ears are often shaped differently, with one ear opening above and one below the owl’s horizontal vision. An owl’s prey is usually heard before it is seen. After the owl turns its head so that each ear picks up the same decibels of sound, the owl is then able to see the prey. The barn owl has the best hearing of all the owls and is able to catch a mouse in complete darkness, using only sounds.
During WWI, parrots were kept on the Eiffel Tower to give an advance warning of approaching airplanes that were still too far away to be seen by the human eye. Also, during WWI, it was thought that pheasants and other birds became disturbed by air waves from explosions that were inaudible to the human ear; however, this has since been attributed not to hearing but to a bird’s sensitivity to vibrations.
Some domestic birds have been used as watchdogs because of their keen hearing. If you’ve ever tried to sneak up on a flock of geese, you know that it is impossible to do so, even if the whole flock appears to be asleep.
Well, it will be a few months before we see robins hopping around in our northern yards in search of worms. Just remember that in the cold and snow of winter there’s a spring that waits to be.
A Blanket of Snow
Diary entry on January 20, 2019: “Woke up this morning to see over twelve inches of snow on the ground and still coming down. I knew the wind was picking up speed when I heard the shutters banging and saw the spruce trees bending. After breakfast, I began shoveling sidewalks and a path to the woodpile.”
Although most people consider a snow storm an inconvenience, in most cases a snow storm is not life threatening. However, deep snow can be devastating to some species of wildlife, especially if the snow remains covering the ground for an extended period of time.
The larger animals (predators) find deep snow a severe challenge. In winters with deep snow, deer will have a tendency to yard up (gather in groups) in stream bottoms, hemlock and other evergreen groves, where they find protection from the snow and wind. To feed, the deer make paths through the deep snow, which enables moving about much easier. Eventually, the food supply in the surrounding area will become depleted. When this occurs, winter mortality will be evident. Usually, the younger deer, which need more food to survive, will die first because they cannot reach as high as the older deer. In one study done, it was found that larger deer can maintain their weight on less food; however, younger deer need either the same amount of food or more to survive.
Predators, such as the foxes, weasels, fishers, coyotes, bobcats, hawks and owls, which stay active throughout the winter months will have a difficult time finding food due to their food supply being hidden by the snow. Voles and mice are vulnerable to predators when the ground is bare. After the ground freezes, their shallow burrows offer little protection from the elements; however, when the ground becomes covered with snow these animals are given some protection from the predators that hunt them both day and night.
These predators keep the vole population in check. If voles, mice and moles, are well fed, they have the ability to reproduce rapidly. A study was done on a well-fed vole, in captivity, which produced 17 litters in one year, averaging five young after a 21-day gestation period. In turn, these young can produce their own litters within one month. If you’re a mathematician, it will not be hard to figure out how many voles this could add up to in a year’s time. However, voles are food for many predators, such as foxes, weasels, fishers, coyotes, bobcats, hawks and owls.
During the winter months, these smaller animals will form communal nests that provide heat. It has been found that a huddled mass of ten voles keeps a nest between seven to twelve degrees warmer at ground temperature and 25 degrees warmer than the temperature above the snow. There are disadvantages of these communal nests, with the competition for food and the increased chance of predators finding nests.
Once the blanket of snow reaches six inches or more the little red squirrel will begin living its life beneath the snow and only occasionally venturing to the surface. The red squirrel will construct an extensive tunnel system under the snow and feed on caches of pine cones it had stored during the fall. As long as the surface ground remains cold the little red squirrel will stay underground.
Rabbits are light enough to walk on top of the snow, enabling them to reach food that is higher. Snowshoe hares, ermines, etc., are protected by the whiteness of the snow due to their fur changing to white during the winter months. Even hibernating animals, such as the woodchuck, benefit from heavy snow. While hibernating, woodchucks keep their body temperature above freezing. This is done by shivering when its body temperature drops; however, shivering, which produces heat, uses up body fat. A snow cover on the ground acts as an insulated blanket, which keeps the frost and cold from penetrating down to the woodchuck’s den.
As the snow deepens and the temperature drops into the single digits, the grouse will fly into a snow bank (snow cave) to spend the night. The snow bank will actually keep the grouse warm. This is because the earth stored up heat throughout the summer, and the snow, being a good insulator, keeps this heat from escaping into the air. The ground would freeze solid if we had no snow. With at least seven inches of snow accumulated on the ground, the temperature at the soil surface rises to 32 degrees and remains constant unless an extreme change in air temperature occurs. It has been recorded that, ground covered with two feet of snow was 50 degrees warmer than the air immediately above the snow pack.
So, when talking about a blanket of snow, we really mean a blanket.