Who's Slept in Westchester This Winter?
Except for numerous white tailed deer eating whatever they can find, rabbits scurrying through the snow, and birds and squirrels at the bird feeder, not much is moving. What are other animals doing? Many find shelter and sleep away the Westchester winter. Let's find out where they are through the coldest months.
In burrows, caves, crevices and under leaves...
Many warm-blooded mammals store a layer of fat just under the skin. They curl up in a tight space and sleep until the temperatures around them dip below freezing. When that happens, they move a bit to keep their body temperature just a bit higher than the surroundings. Skunks, raccoons and chipmunks will sleep for most of the time, but may venture forth during mild spells or wake up to eat some of their stored food. Bears sleep deeply, but can be awakened, so shhhh!
Reptiles and amphibians are cold-blooded, or ectotherms, which means they usually have the same temperature as their surroundings. Without much food around, and with no way to stay warm, these animals find a place brumate. Brumation is a special kind of winter sleep, very still and deep. Brumating animals have almost no heartbeat; they do not breathe or eat. Sometimes the outer parts of their bodies freeze slightly during the winter but it does not harm them because a layer of fat is stored around their inner organs. Box turtles dig in together under rotting logs or tree roots. Snakes curl up together in a snake pit, called a hibernaculum. Land-swelling frogs such as spring peepers and wood frogs have a kind of antifreeze in their bodies that enables them to survive the cold. If you found any of them during the winter, they would seem dead and would not even try to get away from you.
In the mud...
Aquatic turtles, frogs, and certain kinds of salamanders dig themselves into the mud at the bottom of their summer homes, close their eyes, nostrils, and mouths, and stay completely still through the winter. They are brumating.
Some animals are not just sleeping, but hibernating under our feet. True hibernation is defined by an extreme drop in body temperature, a drop so significant as to render the animal as if nearly dead for a time. Metabolism, heart rate and breathing slow to almost a halt. The few mammals that hibernate are woodchucks (groundhogs), brown bats (only they are not underground!), and jumping mice.
Under tree bark or in your house...
Insects that survive the winter also mostly sleep through it. While many, many insects lay eggs and die before winter comes, leaving the eggs or larvae to come out in the spring, a few (some butterflies, beetles and flies) overwinter as adults. On warm winter days, some of them wake up and move around. In very early spring, they will be ready to go again even before the leaves open on the trees.
So, you see, there are many from the animal kingdom sleeping all around us through the winter in Westchester. Watch for the order of their emergence this spring.
Contributed by former staff naturalist, Jill Eisenstein
Friends of the Great Swamp, board member