The Wild Side: Accuracy of the groundhog
February 2 was Groundhog Day. Most of us probably are familiar with Punxsutawney Phil, the Pennsylvania groundhog who steals the spotlight for one day a year. This is a tradition that German immigrants brought over from their homeland, and likely has its true origins in ancient European traditions and ceremonies. It was probably linked to the emergence of an animal from its winter den signaling spring’s arrival.
There are numerous other examples of such beliefs or traditions. “Red at night, sailor’s delight,” referring to using the color of sunset or sunrise to determine the likelihood of storms, has its roots in biblical times. More recently, growing up, my mom always said the width of the black band on a woolly bear caterpillar tells you how severe winter will be. Dad said the bigger the mice make their nests, the worse the winter will be.
When I worked in southwest Minnesota, the Native Americans there had a particular day called an Amber Day once every three months. They would note the weather throughout the day, and use it to indicate how the weather would be for the next three months. These traditions, and many more, were efforts by our ancestors to link nature observation and weather-similar to what we call phenology today.
Is there anything to these predictions? Some more than others, but I think most indicators have an overall accuracy of about 50 percent, which is a coin toss. The emergence of the groundhog is an interesting one to a biologist. The groundhog is a large rodent, related to the marmots that live in mountainous areas. Groundhogs are one of the few creatures we have that truly hibernates. Bears hibernate in a state of torpor. They can move around, give birth, groom, leave and return to the den, and are actually pretty active. Groundhogs almost shut down completely, barely breathing, living off their fat in their hibernation dens, dug below the frost line. Depending on the area, they then emerge in March or April. Maybe it’s how quickly they burn their fat, maybe it’s the frost leaving the ground, or a combination of factors.
So, if the weather signals groundhogs to wake, we might take a cue from them that grass will emerge soon. No sense waking up before there is something to eat, after all. It would be more about when it emerges, not whether it sees its shadow or not.
Still, if nothing else, it gives us something to talk about-the weather is one of the most popular conversation starters we use, after all.
Jeremy Holtz is a wildlife biologist with the Wisconsin DNR in Rhinelander, and writes a weekly column in the Star Journal. To contact him, call (715) 365-8999.