The Reality Behind Groundhog's Day

     Most sources will tell you that the story of groundhog's day, when the groundhog wakes up and leaves his den in the process predicting the arrival (or non-arrival) of spring according to whether or not he sees his shadow, is purely myth. There is, however, perhaps some basis in reality for this tradition:

     Groundhogs are true hibernators. After spending the summer and fall eating as much as possible, they disappear into their dens sometime in October for their long winter nap. Their hibernation chamber is a fair-sized, dry cavern, often located under a bush or tree. There they curl up, tucking their heads between their back legs and go to sleep. As a rule, groundhogs will not wake for the next half year, and it will be March or April before they emerge. During this half year they live off their body fat. They require very little else - their temperature drops to just above freezing, their heart rate slows to fewer than 10 beats per minute, and their breathing and need for oxygen decreases significantly. During this hibernation period the groundhogs sometimes have house guests: rabbits often share the tunnels without disturbing their slumbering hosts.

     What then is the connection between Groundhog's Day, February 2, and the actual habits of groundhogs? According to eNature.com, male groundhogs have been known to wake up in February and venture out to find a mate. Actual mating does not happen at this time - the male simply visits, then returns home for another six weeks of sleep. When he reawakens in March, the groundhog returns to the den of the female for mating, after which he departs and takes no further part in the raising of the family.