It is an overcast day.  Brightly colored birds stand out like jewels in the greyness.  The sparrows blend into the wooded grey/brown of snow-covered shrubs.  The ever-present sparrows and the  winter birds– jays and cardinals, juncos, black-capped chickadees, white-breasted nuthatches and downy woodpeckers– flock to the bird feeder which now has to be filled up almost every day.  The red berries on the bushes are nearly all gone and the feeder is becoming a matter of survival.  On our walks we see empty nests held in the bare arms of winter trees.  An empty robin’s nest is filled with snow– the hatchlings and the mother long gone to fairer climes.  The trees are stripped down to their souls.  With ice storms they become tinkling chandeliers.  In the rain the few remaining dead leaves drip drops of icy tears.

Occasionally a dove visits the feeder.  The chipmunk, who gathered scattered seeds under the feeder all fall, is not to be seen.  He must be in torpor in his den.  According to Bernd Heinrich in: The Winter World: the Ingenuity of Animal Survival, the eastern chipmunk builds a twelve-foot storage system with a nest chamber some three feet down and a network of tunnels which includes a food storage chamber.  Heinrich says chipmunks go in and out of torpor.  He reasons that they would not gather food if they were to be in torpor all winter long.  We will probably not see our chipmunk for the rest of the winter for, in his stuporous state, he would be easy prey.  However he can be roused to eat and venture outdoors if need be, especially in March when there still may be snow on the ground but mating season begins.

The grey squirrels are busy clearing snow from branches as they run along tree limbs.  On the ground they dig through the snow for the walnuts we watched them bury in the ground with their noses this fall.  They do not need to hibernate for they have food stores which they built up in the autumn– and leafy, well-insulated nests.  The red squirrels survive winter by putting on thick, insulating fur.

The back yard is a maze of tunnels.  We think they are deer mouse tunnels as many have tunneled their way into our house.  But they must get by the feral cat who sometimes waits out a snow storm under our deck.  In the woods, the occasional deer waits out the same storm under a squat fir tree. The tracks in the snow tell the story of how they weathered a Nor’Easter.

Beneath the tracks in the snow, in the frozen leaf litter, the insect world is dormant.  Some hibernate.  Others fill their bodies with antifreeze, glycerol, to stay alive.  Heinrich talks about  woolly bears hibernating but they are also capable of freezing solid and surviving, coming to life again as they thaw in the spring.  The pupae, however, don’t survive being frozen.

In Winter: an Ecological Handbook, authors, James C. Halfpenny, Elizabeth Besiot and Roy Douglas Ozonne, tell us that the reptiles and amphibians pick out a “microclimate for hibernation that does not freeze” for their winter, such as the “bottoms of ponds, streams, or deep in the ground.”