In the northern hemisphere, winter is fast approaching. While my beloved squirrels and I are out on all but the coldest of days, many of the animals I see during the warm months seem to disappear. As I contemplate their varied approaches to winter, I am awed by the creative energy that helps life survive.
Thanks to their ability to fly, most of the birds migrate to warmer climates. You might assume the other animals that vanish are hibernating since they do not have the means to travel south. That is only partially true.
True hibernators spend the winter months in deep sleep and are difficult to arouse. They lower their body temperatures so they can sleep for long periods without expending metabolic resources. In my region, only bats, groundhogs, and two species of jumping mice are true hibernators.
Bears do sleep deeply for long periods in their dens, but they are easily awakened and may even go outside if it is warm enough. Because they are still burning calories, bears rely on fat stores to avoid losing muscle mass. Many parks and preserves have been helping the public understand and appreciate bear behavior. “Fat Bear Week” (Explore.org) happens every October. Viewers vote on which bear is the biggest and most ready to survive the long winter.
Chipmunks also spend the winter tucked away, but unlike the bears they only sleep for a day or two at a time. In between, they get up and raid their underground food stores.
The garter snakes who hang around my yard in summer also sleep but add a community approach to staying warm. They get together in cavities and coil in a big heap to keep their body temperatures from dropping to a dangerous level. The hibernaculum may include more than one hundred snakes. Like the bears, they emerge on mild days to soak up some sun and bring that warmth back to the group.
Turtles have a unique way of coping with cold. They settle into the bottom of ponds and lakes and slow their metabolism, like hibernators. Turtles do not sleep, however, and have been spotted moving around under the ice. Turtles breathe air just like we do, but they can hold their breath for months! Whenever I am out for a winter wander, and come across clear ice, I look for turtles underneath.
Like turtles, most frogs hang out in the bottom of ponds. Wood frogs have a completely different approach - they freeze solid! Wood frogs produce a sugar syrup that fills their organs and acts as an antifreeze. Water fills the spaces in between their organs and becomes ice, turning them into frog-cicles. In spring, the frogs come out of suspended animation and go on their way like nothing happened.
The more I learn about the beings around me, the more awe I feel. While on my winter wanders, I send blessings to all the unseen beings who have found wonderful ways to cope with the elements.
From my heart to yours,