Groundhog Day Reprise

(This 984th Buffalo Sunday News column was first published on January 31, 2010.)

Tuesday will be Groundhog Day, which means that we have passed at least the middle of our local winter. And, if Punxutawney Phil or Dunkirk Dave or their many relatives do not see their shadow, we'll be still better off. In that case, winter will end soon. On the other hand, if they do see their shadow, they'll return to sleep for six more weeks.

Nonsense? Indeed, according to some sources. The Farmer's Almanac, perhaps in self-defense, claimed in 1998 that the prediction accuracy is "exactly 50 percent." Another writer argued that a National Geographic Society study showed the prediction accurate "an unimpressive 28%."

Wondering about these wildly differing claims, economics professor Paul Sommers of Middlebury College and his students reviewed all the temperature records following Phil's appearance that were available for the 20th century. They reported their findings in The College Mathematics Journal.

What they found may surprise you, as it certainly did me. When Phil saw his shadow, he was right 68 times and wrong only 10 times, a far from measly .841 batting average. He did far poorer when he didn't see his shadow: right then only one time out of 20. But combining those results, he still batted .704. Not bad for a sleepy little rodent.

You can take that evidence for what it's worth - not much to me. I find of more interest the behavior of this interesting little beast that enterprising politicians dig out every year at this time.

Before going further, let's get its name straight. Groundhog is an alternate name for the animal better known as the woodchuck. It is also sometimes called whistle-pig, a good name because that sharp whistle nearby has several times made me pull up short while hiking.

The woodchuck is one of the true hibernators. According to Allen Benton, among our seven sleepers - the others are jumping mouse, little brown bat, bear, chipmunk, raccoon and skunk – only the groundhog, mouse and bat really do hibernate. The others are far more easily aroused and even venture out occasionally.

But the woodchuck is indeed a deep sleeper. As one naturalist described his sleep: you could bowl him without waking him up.

Under normal, non-Punxutawney conditions, the woodchuck fattens up in fall to make itself about 30% heavier than its mid-summer weight. It is during this period that gardeners lose a good part of their vegetable crop to these herbivores that in other seasons feed largely on grasses. Then in late October the little fatty usually leaves its normal den along a meadow hedgerow to dig another in a woodlot where frost would penetrate less deep. It lines its two to six-foot deep hibernating chamber with leaves and grass, plugs the entrance hole, curls up and falls asleep.

That sleep is studied by space explorers because of its possible application to long-term interplanetary voyages by humans. And you can understand why when you hear it described.

After several days of fitful sleep, the woodchuck drops into full torpor. Its normal temperature is just less than ours, about 97∞ F. That drops to less than 40∞, and the little animal becomes stiff as a board. Its heartbeat reduces from over 100 beats per minute to about four.

The almost lifeless woodchuck remains in this condition for about 100 days. Unfed over that period, its slow metabolism has still used up almost half of its weight. Despite that weight loss, however, both males and females are ready to mate when they finally awaken. They do so shortly after emerging and the females, after a 32-day gestation period, bear young in April or May.

The source of the groundhog's prediction appears to be Pennsylvania Dutch and Amish 19th century traditions, but similar beliefs date back in Europe to the sixth century and involve Old World bears or badgers instead of our New World woodchuck.

February 2 is also a date in the early Christian calendar known as Candlemas and that provides another source of the tradition:

  If Candlemas Day be fair and bright,

    Winter will have another flight;

  But if Candlemas Day brings clouds and rain,

    Winter is gone and won't come again.

You don't really need the groundhog.-- Gerry Rising