Like a Waking Sleep

Bears – Slowing DownMusic JM: This time of year, in northern climates a variety of animals, large and small, are hibernating. But you might be surprised to learn that there are different kinds of hibernation, and that bears in particular, have their own special way slowing down their body’s processes. I’m Jim Metzner, and this is the Pulse of the Planet.DS: There’s two types of animals that hibernate — bears and certain rodents — and the way they hibernate is really quite different. The rodents go into this deep sleep. Their body temperature drops close to freezing. They breathe once a minute. Their heart virtually stops. Bears can’t afford to do that. If a bear were to slow down that much it would take it two weeks to wake back up. So when a bear goes into hibernation its body temperature drops just a little bit about 10 degrees, it’s still relatively close to its operating temperature. And what they’re doing is metabolizing the fat reserves that they built up when they were in hyperphagia.JM: Hyperphagia is when a bear stores fat by eating as much as possible, usually between the months of August through October. According to wildlife biologist David Schirokauer, bears are able to live on that fat during their long winter sleep – by dramatically altering some of their bodily functions.DS: Interestingly though they never have to wake up to defecate or urinate. They have a special mechanism that is unique to bears, where they can metabolize fat, and they can recycle the nitrogen that’s normally a waste product known as urea. But they can recycle that and synthesis proteins with it.JM: The mechanisms of bear hibernation are still not fully understood, however, animal physiologists are currently doing research that could someday have applications for the treatment human diseases. Pulse of the Planet is made possible in part by the National Science Foundation and Virginia Tech, inventing the future through a hands-on approach to education and research.

Like a Waking Sleep

Bears have unique mechanisms for self-preservation during their months of hibernation.
Air Date:12/30/2020
Scientist:
Transcript:

Bears - Slowing DownMusic JM: This time of year, in northern climates a variety of animals, large and small, are hibernating. But you might be surprised to learn that there are different kinds of hibernation, and that bears in particular, have their own special way slowing down their body's processes. I'm Jim Metzner, and this is the Pulse of the Planet.DS: There's two types of animals that hibernate -- bears and certain rodents -- and the way they hibernate is really quite different. The rodents go into this deep sleep. Their body temperature drops close to freezing. They breathe once a minute. Their heart virtually stops. Bears can't afford to do that. If a bear were to slow down that much it would take it two weeks to wake back up. So when a bear goes into hibernation its body temperature drops just a little bit about 10 degrees, it's still relatively close to its operating temperature. And what they're doing is metabolizing the fat reserves that they built up when they were in hyperphagia.JM: Hyperphagia is when a bear stores fat by eating as much as possible, usually between the months of August through October. According to wildlife biologist David Schirokauer, bears are able to live on that fat during their long winter sleep - by dramatically altering some of their bodily functions.DS: Interestingly though they never have to wake up to defecate or urinate. They have a special mechanism that is unique to bears, where they can metabolize fat, and they can recycle the nitrogen that's normally a waste product known as urea. But they can recycle that and synthesis proteins with it.JM: The mechanisms of bear hibernation are still not fully understood, however, animal physiologists are currently doing research that could someday have applications for the treatment human diseases. Pulse of the Planet is made possible in part by the National Science Foundation and Virginia Tech, inventing the future through a hands-on approach to education and research.