Animals in Wintertime
As I write this, it is minus five degrees F outside, with no snow cover on the ground. Brrr! What are you doing to stay warm? Do you wonder what chickadees, shrews and groundhogs are doing on a night like this? For non-migrating animals this temperature, coupled with the lack of a blanket of snow, makes for a cold night indeed. Animals that overwinter in Vermont must cope with not only the cold but also the limited supply of food.
There are many animals that leave our hillsides and valleys, abundant with food in the spring and summer, at the first sign of pending frost. All who leave Vermont do so by air—no hoppers or waddlers would venture the dangers of a 1000-mile trek. Wings are handy when it comes to long distance travel. So, long-legged great blue herons, and delicate monarch butterflies newly hatched from the safety and warmth of their cocoons, join the ranks of red bats and black-throated blue warblers and sharp-shinned hawks migrating to warmer climates. Despite the convenience of wings, they will face many dangers and perils along the way, and some will not survive the journey.
For the porcupine and the white-tailed deer, among others, the risks of a bitter cold night are chosen over the dangers of travel. Each species of animal that stays in Vermont has, over time, developed adaptations and strategies to cope not only with the cold, but also with the lack of available [PJ1] plant food. Some, like the red fox, the weasel and the snowshoe hare remain active all winter. While others, like the groundhog and little brown bat hibernate. And still others, like the chipmunk, raccoon and skunk enter a semi-hibernating state in which they generally stay in their dens nibbling on caches of food between periods of inactivity.
Some mice—the white-footed and the deer mice—stay active all winter, while both the woodland and meadow jumping mice hibernate for up to six months. Winter survival strategies also vary for members of the squirrel family. Some tree squirrels— gray and northern flying squirrels especially—stay above ground all winter because they are able to find food on trees. Whereas other squirrels—chipmunks, red squirrels and groundhogs—spend some or all of the winter below ground in extensive burrows. The chipmunk builds an especially elaborate system. Their burrow is often as long as twelve feet, and will include a nest chamber some three feet underground, food-storage chambers, escape tunnels and a main work hole!
Groundhogs, whose diet of fresh plants including garden veggies, like lettuce, peas and beans, doesn’t store well in a moist underground burrow, hibernate in the truest sense of the word. While hibernating, their body temperature will drop from about 98 to 37 degrees F. Their heart rate drops from a robust 90 beats per minute to only four or five a minute. And, they will take a breath only once every three or four minutes. Of course, the thick layer of fat they acquired in the bountiful days of summer is serving them well now as it acts as both a blanket and a source of nourishment during these cold, lean days.
The animals that remain active in Vermont throughout the winter have to resort to much cuddling, shivering, eating, hunting and generally moving about. A chickadee’s feathers will double in number as winter approaches and a deer’s hollow hairs help to trap heat. Some animals are able to go into a temporary state of hypothermia in order to reduce their metabolism during especially cold nights. Grouse grow a fringe of horny projections around their toes, which act like snowshoes to keep these stocky birds from sinking into the snow.
All this is happening just outside our back doors, and clues to these animals’ whereabouts are just waiting to be discovered.
To learn more about animals in wintertime and how to track animals, join us at BEEC for our annual Winter Adventures Camp which will happen daily this year from February 20 -24, for children in grades 1 through 4. Each day offers a different lens into the world of animals in wintertime.
Monday: My Side of the Mountain
Tuesday: Tracking the Golden Grouse
Wednesday: Art for Animals
Thursday: Animal Survival Strategies
Friday: Snow Play!
For more information about BEEC and our upcoming vacation camp, visit us at www.beec.org or call 802.257.5785