The bear exhibit at the zoo offers a unique view or adaptation in these large mammals. It is an enlightening experience. Naturally, I am particularly interested in the description of hibernation because hibernation is a perfect example of a prolonged and extreme famine. How do bears adapt to this threatening environment, completely devoid of food—and water?
Weight Loss Tips For Teenage Guys The Bear Facts Photo Gallery
The bear exhibit featured a reproduction of a bear den with a brown bear curled up inside and snow thickly packed on top. The exhibit offered a complete explanation of this phenomenon right next to it.
This is what it said: During the fall months, grizzlies and black bears prepare for hibernation [famine] with a bout of frenzied feeding or hyperphagia. They might feed for up to 20 hours and consume 20,000 calories a day—about five times their normal intake! They become very fat, but they have consumed, almost to the calorie, the amount of energy they need [to survive] during hibernation. The fattest bears hibernate first. The thinner bears continue to eat if food is available.
What’s going on during hyperphagia? It is simply excess eating for the purpose of fat storage as preparation for hibernation. It’s actually a protracted binge. How does it happen? Why does it happen?
Bears in distinct seasonal climates hibernate annually, during the winter months. This experience is established from birth. These are the conditions of hibernation:
• no external food or water intake (severe famine)
• dramatic drop in metabolic rate (adaptation to famine)
• no physical output whatsoever (adaptation to famine)
The perfect famine state is accompanied by a perfect drop in metabolic rate to the lowest possible level to maintain life. Bears go into a deep sleep, which allows for near metabolic and physiological stasis. This state is maintained until spring when famished bears leave their dens and seek food again. This spring eating and regaining of weight gradually culminates in the hyperphasia of autumn when they again prepare for hibernation. And so, the cycle goes.