Hibernation Explained: Vital for Some Species, but Not Humans

The cold weather is very tempting to just lie on a warm bed and sleep throughout the winter. Sleeping during a cold night might be comforting for humans, but it is so much more for some animals.

Hibernation is an involuntary process in animals that is essential for their survival. It helps animals to conserve energy during this season. Extreme metabolic changes occur during hibernation, such as the heart rate and breathing slow down, and body temperature drops.

Some species in hibernation may sleep for weeks without walking, drinking, eating, or relieving itself.

Hibernation Helps Endothermic Animals

Animals who go into hibernation are the bats, rodents, three lemur species, bears, groundhogs, and other animals. These endothermic animals, or warm-blooded animals, become completely incapacitated during winter, making it impossible for them to wake up.

Warm-blooded animals need a constant source of energy to generate body heat internally. The winter months are when the food source is scarce, so hibernation helps them conserve their energy. When they wake up in spring, they feed heavily and build fat because the food at that time is plentiful.

Although most animals that hibernate experience many physiological changes during this time, bears only experience less severe changes in which their body temperature can stay at normal levels within 12 degrees Fahrenheit, which allows them to react when sensing any danger.

Moreover, amphibians and reptiles have a different kind of hibernation called brumation. During this time, they stay dormant to escape the cold but will move on warmer days to look for water. Some species like wood frogs and woolly bear caterpillars are capable of producing natural anti-freeze that stops their cells from freezing entirely in the winter, according to Teatown.org.

Preparing for Hibernation

According to the Encyclopedia, animals start preparing for hibernation during the fall by storing enough energy to last them throughout the winter until spring. For instance, chipmunks would fill their burrows with food, which they consume in periodic arousal from sleeping throughout the winter.

But most animals store energy as fat like the woodchuck, whose fat increases to 15 percent from 5 percent only before the fall, or the dormouse, which can have a fat equivalent to 50 percent of its total weight by the time hibernation starts. Animals usually have a feeding frenzy followed by a short period of fasting before hibernation to ensure that their digestive tract is completely emptied.

Why don't humans hibernate?

There is no need for humans to hibernate because biology and technology keep them comfortable all-year-round. Also, the ancestors of humans mainly come from tropical areas that need not hibernate. According to Science Focus, it was only a few hundred thousand years ago when they migrated to sub-arctic regions, which are not long enough to evolve adaptations for hibernation.

In terms of technology, humans discovered fire, clothes, shelter, and agriculture, which are effective ways of surviving the winter season. Ancient humans with clothes would have easily won over those who tried sleeping their way through the winter.