HIBERNATION is one of nature’s most fascinating processes. The word hibernation means “winter sleep”. However it is more than simple slumber.
Hibernating animals may appear to be dead when they are in a deep state of hibernation. However, some hibernating animals sleep and wake periodically or sleep on a much lighter level. They may became active on warmer days and eat some of the food they have stored before going back to sleep again.
Nature, in her wisdom, has good reason for hibernation. It allows certain warm-blooded animals to survive a long period of cold weather and food shortage.
As winter approaches, before the winds roar at their worst and snow piles high on the ground, an animal that hibernates will instinctively find a safe out-of-the-way spot to sleep in. Before hibernating, the animal eats enormous amounts of food and grows fatter. At the same time, it grows slower and slower in its activity, until it is ready to fall into a stupor. At this point, it curls up in its sleeping place.
During hibernation, an animal’s bodily processes and movements slow down drastically and are maintained at the lowest possible level to keep it alive. All movement of the animal ceases. It looks and feels cold and lifeless. The animal’s heartbeat becomes exceedingly slow. In summer, a woodchuck’s heart beats at least 80 times per minute. During hibernation, the heart rate drops to about four beats per minute.
Breathing becomes so shallow that it cannot be observed. During summer, a woodchuck breathes about 25 times per minute. During hibernation, he breathes only about once every five minutes. During summer, his average body temperature is 97*F. During hibernation, it drops two as low as 38*F.
The bear, perhaps the best-known hibernators goes into a deep winter sleep and does not wake up until the weather grows warmer and food is readily available. The bear’s state of hibernation is not as deep as the woodchuck’s and his body changes are not as drastic. His body temperature even remains at its normal high level.
Warmer weather temperatures and hunger will awake a hibernating animal during its long sleep, it has used up the fat stored in its body and may have lost over a third of its body weight after awakening. At the same time, its body temperature and other processes return to normal. The animal begins to eat and quickly regains its full strength and weight. Usually, it are the animals that eat vegetables and live in a cold climate that hibernate (such as bears, bats, badgers and squirrels). Almost all burrowing animals are hibernators. Nature has truly devised means to protect her creatures, great and small.
