Why Is It That, Mammals Hibernate?
Woodchuck is typical hibernating animal. The squirrel stores up the food supply in winter. It depends on plant food and with onset of winter its food supplies vanish. The woodchuck has stored up a reserve supply of fat on its own body. Not finding food it crawls deep into its burrow and goes to sleep. It sleeps through the cold winter and lives on the fat which it has stored up. The word “hibernate” comes from the Latin and means ‘winter sleep’.
The bear like many mammals do not sleep deep in hibernation. On warm and pleasant days in the winter, the bear, the squirrel, the chipmunk will wake up and come out in the open.
The sleep of a hibernators is almost like death and is not like ordinary sleep. All activities of an animal in hibernation nearly stop. The body temperature decreases until it is a little warmer than that of air in the den.
The animals burn the stored food in their bodies slowly. They burn less fuel, they need lees oxygen and thus as a I 11lt their breathing is slower and their heart beat goes faint. With further lowering of den temperature, the animals wake up, dig itself in a little deeper and goes to sleep once more.
With the coming of spring, the animals are awakened by the change in temperature, moisture, and by hunger. They crawl out of their dens. The cold-blooded animals hibernate also. Earthworms crawl down into the earth below the frost line, frogs burry them-selves in the mud at the pond bottom, Snakes crawl into cracks in the rocks or holes lathe ground. A few fish, like carp, bury themselves in the mud at bottom. Even some insects hibernate by hiding or under logs or rocks.