Ever wonder what our local wild animals are doing during the winter months? Are they hunkered down, hibernating, half asleep, just waiting for spring? Some are, some aren’t.

Out of all the different wildlife species in New Hampshire, for example, only seven sleep the winter away to some degree. Three of these (bats, woodchucks, jumping mice) are true hibernators, drastically slowing down their body functions. The other four (chipmunks, raccoons, striped skunks, black bears) simply slow down a bit to conserve energy during really cold periods. They can remain “napping” for weeks until a warm spell allows them to emerge and look for food.

Bats – There are 8 species of bats in New Hampshire. Five of these have winter dens or hibernacula and a couple will spend the winter sleeping in our homes (see What Do Bats Do in the Winter?). Bats first increase their body weight by up to 25% as these reserves have to last about 7 months. Then they hang upside down in their dens, lowering their heart rate from 210 beats a minute to 8, and their body temperature from 100° to 40°.

Woodchucks  – In late summer after fattening up, woodchucks sometimes build a separate hibernation burrow that they enter in late October to early November (see Yes, Woodchucks Do Too Hibernate). They lose about 30% of their body weight during their 5+ month hibernation. In rare cases, they may break hibernation and can be seen briefly foraging outside.

Chipmunks – During its winter rest, a chipmunk’s body temperature drops from about 106° to 43°. Chipmunks have wake-up periods though throughout the winter when they will wander outside, looking for their hoarded nuts and seeds.

Raccoons – Raccoons can be more of a nuisance than usual in fall as they raid garbage cans to fatten up for their winter “naps.” They then lose up to 50% of their weight during winter months. Raccoons den up individually in hollow trees, rock crevices, other animal’s burrows, or in attics or chimneys (see Winter Raccoons Denning in Attics).

Striped Skunks – Female skunks may den together in sites such as burrows, hollow logs, or under sheds, porches, or decks. Skunks remain denned and “asleep” when temperatures are below freezing. But, when nighttime temperatures are above 30°, skunks can become briefly active searching for food (see What Do Skunks Do During the Winter?)

Most of these winter sleepers can become pests during warmer weather when they move into, or visit, residences. At Colonial Pest, we have certified nuisance wildlife specialists on staff who are able to trap or deter these animals when they become urban or suburban pests. Our technicians are also experts at pest-proofing homes to seal openings that these pests can use to get inside or to establish dens. However, we prefer to leave black bear management to the state wildlife folks instead!

[Source: A Long Winter’s Nap by Patrick Tate, New Hampshire Fish and Game’s furbearer biologist. Wildlife Journal, Nov-Dec 2009]

Photo Credit : Public Domain