MDC naturalist explains how wildlife survive winter on their own

CAPE GIRARDEAU, Mo. – Missouri Department of Conservation (MDC) Naturalist Alex Homes said though the motivation may be sincere, “there’s no need to rescue wildlife during wintertime,” as each species knows how to endure Mother Nature.

“They each have their own time-tested method of surviving,” he said. “The season is indeed difficult for some, but they each know how to survive.”

Some animals migrate, hibernate, and others may simply hideaway and keep warm, Holmes said. For instance, woodchucks, or groundhogs, are “true hibernators,” he said.

“In late summer, woodchucks fatten up to prepare for a deep sleep that usually lasts until winter is over,” Homes said. “They conserve energy reserves while sleeping by lowering their body temperature by about half, and by reducing their heartbeat down to about four to five beats per minute.”

Other true hibernators include Franklin’s ground squirrels, meadow jumping mice and some species of bats. Bears are commonly categorized as hibernators, “but they aren’t,” he said.

“A bear’s sleep is not as deep as a groundhog’s,” Homes said. “They fatten themselves before winter and their heart rate drops, but their body temperature doesn’t go down much. Female black bears are usually pregnant when they sleep, and the offspring growing inside them need the warmth,” he said.

Frogs, snakes, and turtles don’t hibernate, but they go into what’s called torpor, or a dormant state that closely resembles death, Holmes explained.

He said green frogs spend winter in the mud at the bottom of ponds, and box turtles bury themselves in soft ground. Snakes find shelter in a den or crevice and may spend the winter in a tangle of other snakes – sometimes not all the same species.

Some frogs, including Missouri’s Wood Frog, deal with lower temperatures by becoming slightly frozen. “The livers of these frogs secrete a sugary substance that allows them to freeze without dying for up to a few weeks,” Homes said.

Skunks, raccoons, and opossums don’t hibernate, but will nap in dens, trees, or logs during the coldest parts of winter, he said. “Their naps might last weeks, but when the weather turns balmy, they venture outdoors. These nocturnal animals may also switch to searching for food during the day to avoid colder night temperatures.”

“This is a great time to go on a hike or go out in your yard to look for tracks, scat and chew marks to see who’s been out and about,” Homes said.

He said taking photos of tracks and scat with something else in the photo works great for a size comparison. The photos can then be used to compare with MDC’s online field guide for identification of who left the tracks.

Find out more about wildlife survival techniques at mdc.mo.gov.