by Robin Follette

Hibernation is underway in our woodlots. We can let the dogs out in the evening without worrying about them bumping into raccoons, skunks, porcupines and bears. Or can we?

Late one December I stumbled upon a soaking wet carcass. I assumed from its black fur that a neighbor’s cat had fallen prey to a coyote or fox until I got closer. The smell wasn’t strong but it was unmistakable and I didn’t need a closer look to know that a skunk had come out of hibernation for a walk in the snow.

In elementary school, we learned these animals fell asleep in a cozy den and didn’t wake up until spring. I was in awe of the bear’s ability to give birth while sleeping, and of the cubs’ ability to find their way to nurse all winter. Should have known that was too good to be true.

There are only three true hibernators in Maine. The little brown bats, struggling with white nose syndrome, go to their hibernacula in September and October to spend the winter, and don’t emerge until early to mid-spring. Unless you have a cave, mine or empty building in your woodlot you probably don’t have hibernating bats. The little brown’s heart rate drops from one thousand beats per minute to five.

Have you noticed resident groundhogs giving your late-season garden a break? They’re the second of Maine’s true hibernators. Like the little brown bat, groundhogs settle in from early to mid-fall. They dig a den near the tunnel where they spend the rest of the year, located below the frost line and above the water table. Body temperature drops to 38°, heart rate to four beats per minute, and breaths to ten an hour. If groundhogs are hibernating in your woodlot they’re likely at the edge, near a clearing.

Meadow jumping mice, the third true hibernator, do well to survive winter, though many don’t. Unlike most animals preparing for winter, jumping mice spend only two weeks fattening up. Their den is a small chamber less than two feet below the surface, often beneath logs. Once dug, jumping mice line the chamber with dry plant material, close the opening with soil, and don’t emerge until spring. Unlike other rodents that stash seeds, jumping mice don’t need them. They won’t wake to eat or drink.

We often see our part-time hibernators, skunks and raccoons during January thaw before the coldest part of winter sets in, and again in late February. In mild winters like last year’s, both were out for two weeks, on Feb. 1 (raccoon) and Feb. 3 (skunk), according to our game camera photos.

We know now that bears aren’t especially sound sleepers. They seldom leave the den in winter and even then don’t go far, and don’t eat or drink. In the 18 winters we’ve spent snowshoeing our woodlot and surrounding woods, I’ve seen bear tracks only twice. Loggers sometimes rouse a bear out of the den by moving a pile of logs, or even a single log.

We’re more likely to find tracks than the part-time hibernators themselves while out in the woods, but take a look. Tracks tell us what animals were out and about when least expected.

Only Three Maine Mammals Hibernate Full-Time