Getting Ready for the Big Chill
As winter begins drifting into Ohio, people are pulling on parkas, adding extra blankets to their beds and building cozy fires to keep away the cold. But what about wildlife? How do they survive the cold months of winter?
Evolution has prepared wildlife to cope with the climatic changes they face in their neck of the woods. Some animals hibernate and some migrate, while others stay put, growing thick coats and consuming extra food to keep them warm. Whether hibernating or staying active, body fat is an important factor in an animal's winter survival. In the fall, birds and mammals eat extra food so that when supplies are scarce, their bodies can draw energy from fat reserves.
Hibernation is one of the most intriguing methods animals use to survive cold weather. When an animal hibernates, its heart rate, body temperature and other life processes slow down, putting them into a kind of a deep sleep.
Groundhogs, also known as woodchucks, are one of Ohio's true hibernators. During a groundhog's hibernation, which lasts an average of five months, its body temperature lowers by almost half and its heart slows down from 160 to four beats per minute.
When outside temperatures drop dangerously low, skunks, raccoons, chipmunks and opossums are known to go into a temporary hibernation. During those frigid periods, they seek shelter in trees, logs, beneath rocks or underground where they "œhole up" and sleep for about five days until the weather breaks.
Snakes, turtles, frogs and most other cold-blooded animals crawl into holes or burrows where they remain inactive all winter. Some snakes gather family-style in the same den and weave together in a ball to help insulate themselves.
Although most of Ohio's frogs hibernate on the bottoms of ponds and streams, one native amphibian prefers staying on land and becoming a "œfrogsicle." The wood frog prepares for winter hibernation by burrowing under the forest floor. Falling temperatures trigger a chemical reaction and the wood frog begins producing a kind of froggy antifreeze. Large amounts of proteins and sugars pump through its credit-card size body, keeping cells from freezing and preventing dehydration.
As the winter deepens, the truly remarkable happens: 45 percent of the frog's body water turns to ice, its eyes and brain freeze solid, and its heart and lungs stop. Come spring, the wood frog quickly thaws and is the first frog in Ohio to come out of hibernation. The wood frog has an easily recognizable raccoon-like mask across its eyes and can be found throughout the eastern two-thirds of Ohio.
Many migrating birds fly thousands of miles away from Ohio, seeking warmer climates and nutrient-rich habitats. For non-migratory birds such as cardinals and some robins, packing on a few extra ounces of fat is not enough. With their warm season diet of insects, worms and other invertebrates no longer available, they switch to a winter diet of seeds and fruit, consuming the likes of crabapples, wild berries and weed seeds.
Other flying creatures, such as the Indiana and little brown bat, not only migrate they hibernate! Roosting inside dark, comfy caves, these bats often ride out winter just south of the Ohio border.
Watching wildlife scurrying along the ice and snow can tug at the human heart strings, but with the exception of feeding songbirds, putting out food for wildlife can hurt more than help. The unnatural gathering of many species to one food source can promote the spread of disease. Feeding bread to ducks and geese is terrible for their digestion and waterfowl are especially vulnerable to outbreaks of botulism when artificially fed. Deer that are fed all winter become accustomed to the free meal and think it's perfectly acceptable to munch in flower beds and vegetable gardens in the spring and summer.
The best way to help animals weather the winter is to make your yard wildlife friendly with naturally grown food and shelter. Best bets include trees that yield nuts and berries, and evergreen trees and shrubs such as pines and taxus yews that offer animals protection from wind and rain. If you own a larger parcel of land in the country, brush piles and thick patches of briers provide excellent winter cover for bobwhite quail, cottontail rabbits and other small animals. Planting food patches of corn, sorghum and millet give numerous wild animals a good source of energy to maintain their body heat in cold weather conditions.
- Laura Jones
ODNR Office of Communications