As winter temperatures drop to -30C across parts of Canada, the thirteen-lined ground squirrel nestles one-metre underground in a grass-lined burrow for six months of the year. It avoids the harsh weather and lack of food by slipping into a deep sleep known as torpor (too bad we can’t all do that sometimes). Its body temperature plunges to just a few degrees above zero, its heart barely beats, and it hardly breathes. It would be too dangerous to remain in torpor all winter, so these squirrels re-warm themselves every ten days or so to maintain brain function and sleep. They need to wake-up to sleep. As the brain begins to warm up, the squirrel shivers — a way to increase blood flow to almost frozen muscles and organs. Like waking up with a huge hangover, the squirrel has temporary brain damage and suffers from memory loss and disorientation. It apparently takes 30 minutes to become fully functional again.
(Source and Image:cbc.ca)