Winter in the temperate zone is a time of short days and long cold nights. Temperatures can drop to freezing, cold winds blow, snow falls, and food is in short supply.
Some animals move to warmer climates during the blustery months of winter. Many Washington, D.C., songbirds spend the spring and summer in northern breeding grounds, then migrate south to warmer climates where food is still available.
Other animals, like groundhogs, chipmunks, and some local bats, have the ability to lower their heart rates, respiration, and body temperatures in a state of hibernation. This allows them to get through the winter using up very little of their energy supply.
Insects have to survive the cold as well. Some do this by spending the winter as larvae, while others overwinter as adults in large colonies keeping each other warm. Some insects simply die off after leaving behind their eggs. A few insects have evolved the ability to produce glycerol in their blood that acts as an “antifreeze” to allow them to survive the cold.
Those animals that stay active throughout the winter have also evolved ways to make it through until spring. Birds and mammals have feathers and fur that are good insulators, trapping warm air close to their bodies. Squirrels, for instance, will use their large, fluffy tails as windbreaks to protect their backs and heads. Foxes wrap their long, furry tails around their faces to keep them warm while they sleep. And birds fluff up their feathers to allow for a larger area of warm air around their bodies.
Whether they stay or move on to warmer climates, hibernate
through the cold winter, or scratch out a meager existence
in our winter wonderland, most animals fare better with the
return of spring’s warmth and bounty.
