Chris Slingsby, age 12, of Costa Mesa, California, for his question:
Do hibernated animals breathe?
We tend to think of animal hibernation as a sort of deep sleep. But this slumbering condition is far more extreme than the deepest sleep that we experience. It has been compared to a coma, somewhat like a fainting spell. But this comparison also falls short of the mark. A hibernating animal is in a sort of suspended animation. He is not dead, but neither is his body carrying on the normal processes of life. However, his main functions are operating at a minimum level. His body cells need oxygen, but in the repose of hibernation they can do with very little.
The pulses and respiration of a large variety of hibernating animals have been checked by researchers. Heart beats slow down to one per minute or even slower. There is a corresponding slowdown in the breathing process. The pulse may be so faint and hard to find that it seems almost non existent. But animals that depend on lungs do breathe during hibernation. Amphibians can absorb oxygen through their skins. As a rule, during hibernation they use this method rather than breathing through their lungs.