"Trees in winter." Illustration by Carolyn Newberger

Illuminating the Hidden Forest, Chapter 25: Hibernation

For me, winter in the Berkshires involves quite a bit of curling up on a window seat in my snug den, maybe with a book in hand, my dog lying on my tummy, looking forward to an afternoon nap and an early bedtime.

To read the previous chapters of ‘Illuminating the Hidden Forest,’ click here.

Dec. 19, 2019 

These are dreary days in the Berkshires. The snow is slush, the sky is gray, and I linger over coffee in my bathrobe, thinking idly about getting dressed. After her morning kibbles, Lily returns to her bed. In early afternoon I settle down for a nap on the couch. It’s time to talk about hibernation.

As I look over the back patio and into the woods, things are quiet. When the wind blows through the treetops, I might hear a hollow clack and occasional squeak of limb against limb, or the sound of a dry leaf skittering across the landscape. The chipmunks are no longer nibbling up stray seeds fallen from the birdfeeders, though the birds are dropping seeds by the handful.

Not only by the calendar, but also by the feel of things, winter is here. By now, the bears are in their dens, maybe to emerge drowsily from time to time on a warmish day. Scientists debate whether they hibernate. Obligate hibernators are critters like ground squirrels, who enter their dens for winter whatever the temperature or whether there’s still food on the ground, lower their temperature, slow their heart rate and breathing, and are more or less out for the count for whatever is their obligated duration. Other creatures, like bears, are called facultative hibernators, who respond to feeling cold and hungry by crawling into their dens and just slowing everything down.

Even deciduous trees, it appears, hibernate. Starting in late summer, they draw into their bodies nutrients from their leaves before dropping them, seal off the branch tips, slow their metabolism, and quietly rest out the winter. Their bark protects them from the elements and dehydration.

Scientists these days think of hibernation as being on a continuum. Some animals enter deep dormancy while others rouse from time to time to relieve themselves and eat a nice meal from the cache they put aside in fall. I was pleased to learn that one primate hibernates: the fat-tailed dwarf lemur of Madagascar. This lemur hibernates not when it gets too cold, but when it gets too hot. He or she finds a nice insulated hole in a tree, which protects against fluctuations in temperature, goes in, curls up, and slows everything down for about seven months of the year.

This leads to the question: “Where are we humans on the continuum?”

For me, winter in the Berkshires involves quite a bit of curling up on a window seat in my snug den, maybe with a book in hand, my dog lying on my tummy, looking forward to an afternoon nap and an early bedtime. Is this a variant of facultative hibernation, albeit, fortunately for me, without food deprivation?

My human form of facultative hibernation seems to be light-sensitive. When the sky is gray, whether or not snow is falling or the temperature frigid, my metabolism seems to slow, I consume a larger dose of hot liquids and indulge in more frequent naps on the couch. When the day is crisp and bright, my faculties rouse, I strap on my crampons and head for Kennedy Park with Lily, who seems to share my enthusiasm if the sun is out and the snow isn’t deep.

I think about friends who spend their winters in Florida. Perhaps they are missing the benefits of human hibernation in colder climes: making up for the lost sleep of summer; tummy time with a warm pet; several months each year when slowing down feels like the right thing to do; a little more quiet time with friends; a time of restoration.