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I'm reading Winter World by Bernd Heinrich, an author I know from Ravens in Winter and Mind of the Raven. Some facts:
* Hibernation is pretty much about getting past food shortages, not cold per se. Animals with enough food stored up or otherwise available are happy to frolic all winter.
* Hibernating mammals rouse themselves multiple times to enter REM sleep. This can cost them half their winter energy expenditure. Apparently having a body temperature of 3 C doesn't exempt you from sleep deprivation and it's important to do something about that.
* Word of the week: sub-nivian, or beneath the snow. As in chipmunks live in a hidden sub-nivian world of snow tunnels and food caches. Wikipedia spells it "subnivean climate".
* Hibernation is pretty much about getting past food shortages, not cold per se. Animals with enough food stored up or otherwise available are happy to frolic all winter.
* Hibernating mammals rouse themselves multiple times to enter REM sleep. This can cost them half their winter energy expenditure. Apparently having a body temperature of 3 C doesn't exempt you from sleep deprivation and it's important to do something about that.
* Word of the week: sub-nivian, or beneath the snow. As in chipmunks live in a hidden sub-nivian world of snow tunnels and food caches. Wikipedia spells it "subnivean climate".