HIBERNATION
I chose to write my paper on how animals hibernate. How some are true hibernators, how some are not, how some will just blow you away at how they spend their winters, and why science is trying to use this process with humans.
When you mention hibernation, generally most people think of bears, but in actuality most bears are not true hibernators.
[pic]
Grizzly Bear
The Grizzly Bear is a large bear with a muscular hump on its shoulders. Not a true hibernator.
To be a true hibernator you must have a huge drop in heart rate, body temperature and metabolism, resulting in long-term dormancy. In this state the animals body temperature is only a few degrees above freezing, the oxygen consumption is down to 2% of normal, and the heart rate drops from up to 300 beats a minute to just three or four beats per minute. Also these animals are very hard to awaken.
Bears do go into a dormant state where their heart slows down but are generally not true hibernators because their body temperature stays relatively high and they are easily aroused. Also where other animals wake up periodically, eat, and excrete bodily fluids, bears do not.
Frog [pic] Many frogs are dormant during freezing weather.
Reptiles like the turtle and frog are quite amazing. Some frogs spend their winters at the bottom of lakes or ponds where the temperature remains a stable 1 to 4 degrees Celsius. Being able to absorb the oxygen from water through their skin they have adapted to survive the cold winters. Reptiles like the turtle with tougher skin and shell have a harder time, but have adapted to absorb oxygen across the skin lining of their throat, where other turtles such as the Painted Turtle have actually altered their metabolism and have adapted to be able to survive at 0% oxygen intake. They can survive for as long as 3 months with zero blood oxygen. Humans on the other hand suffer irreversible nerve damage if oxygen supply to the brain is cut...