Rolling with the punches of winter weather

Though the recent cold and snow already seem a distant memory, they prompted many interesting e-mails asking the same question. What happens to the wildlife in areas when low temperatures and huge amounts of snow fall in a matter of days?
The short answer is, "Not much." Most species are adapted to cope with winter weather. Many, including invertebrates, frogs, turtles, snakes and some mammals, simply shut down and enter a season long torpor.
Two common aquatic mammals deal with winter much like we do: They build shelters. Muskrats and beavers build lodges with underwater entrances. Even when their ponds freeze over and are covered with snow, they slip freely into the water to feed on aquatic vegetation (muskrats) or the bark of limbs and branches (beavers) they've stored under the ice. Though muskrats are limited to wetlands or stream banks with sufficient water to cover their den entrances, beavers can manipulate their habitat by building dams to create ponds where food is available.
Throughout the year, myriad aquatic invertebrates, fish, frogs, turtles, snakes, waterfowl, wading birds, swamp sparrows, prothonotary warblers and mammals such as mink, otters and raccoons enjoy the fruits of the beaver's engineering expertise.
Not bothered much
Squirrels rarely are bothered by winter weather. They fatten up in the fall and store caches of food they use throughout the winter. On days when the thermometer barely climbs above zero, they wisely stay in their dens. I didn't see any fox squirrels at my feeders recently until daytime highs reached into the 20s.
Chipmunks and flying squirrels are much smaller than tree squirrels, so they lose body heat more rapidly than their larger kin. Chipmunks respond by hibernating. They simply spend the winter in subterranean burrows where they occasionally wake to eat some of the seeds they stored in their underground retreats. Because chipmunks wake periodically to eat, one can argue they are not true hibernators.
Flying squirrels, like other tree squirrels, do not hibernate; they roost communally during the day to reduce heat loss. A half dozen or more flyers may cuddle during daylight hours before venturing out on nocturnal foraging trips.
It turns out that cuddling is an effective technique for reducing heat loss and staying warm. Deer mice and bluebirds roost communally in old woodpecker holes, and out west, pygmy nuthatches sometimes roost by the dozens in large tree cavities. Even tiny golden-crowned kinglets huddle through the night in the north woods, protected only by the branches of conifers.
On the other side
In nature, however, for every adaptation there is often an equal counteradaptation. Weasels, with their long lean bodies, find their way into chipmunk dens for easy meals. Mink can plunder muskrat lodges. Fishers and pine martins wreak havoc on squirrel dens. And when ice melts, raccoons no doubt find sluggish frogs and turtles easy meals.
As I pondered how wildlife deals with extreme cold and snow, I concluded that most species can handle almost anything that nature delivers. Two exceptions, however, come to mind. Ice storms are devastating because ice forms an impenetrable barrier. Ice traps things beneath and above it. It makes foods almost unattainable. This is the one time it is essential to keep bird feeders well supplied.
If an ice storm persists for more than a few days, many critters surely die. But scavengers consume the remains, and we rarely see the aftermath. Fortunately ice storms are not annual events.
Heavy snows, more common in Michigan and upstate New York, can also be problematic for larger species. Where deep snow is more the norm, deer commonly migrate to winter ranges where cover is better. These "deer yards" are typically in dense lowland conifer forests where snow depths are less, and winds and temperatures are moderated. Food quality in these areas is poorer so deer must rely more on stored fat. A hard late winter, such as this one, is usually manageable because deer entered the season well fed.
Wild animals can deal admirably with almost any conditions winter offers. When winter weather turns extreme, my advice is to worry more about people than wildlife.
Send questions and comments to Dr. Scott Shalaway, RD 5, Cameron, WV 26033 or via e-mail to sshalaway@aol.com.