Groundhogs don’t have a clue about winter


This Friday, news media and throngs of other silly folks will gather near the small Jefferson County town of Punxsutawney well before dawn to celebrate one of our most ridiculous unofficial holidays: Groundhog Day.

This daffy ritual consists of a cadre of jokers in top hats and tails dragging a groundhog from a contrived burrow and holding the dazed-looking rodent in a stranglehold while proclaiming whether it did or did not see its shadow, all the while being blasted by TV lights and photo flashes. And the presence or absence of said shadow foretells either the end of winter or another six weeks of winter. As much I enjoy folklore, legends and traditions, especially ones that have roots here in Pennsylvania, I find Groundhog Day and all the hoopla surrounding it a complete waste of time.

Groundhogs are actually the largest members of the squirrel family found in Pennsylvania. Although groundhogs spend most of their time on the ground, they are excellent tree climbers and swimmers. They are also known as “woodchucks,” but this has nothing to do with any association to wood. It comes from a convolution of “wuchak,” which is the Algonquian name for this big ground squirrel. Some folks also refer to groundhogs as “whistle-pigs” because when alarmed they will emit a high-pitched whistle to alert others to the potential danger.

Groundhogs are herbivores that eat wide variety of wild grasses, clover and other leafy vegetation. Their fondness for agricultural and garden crops makes them quite a persistent pest to many farmers and other landowners. Groundhogs have relatively small home ranges, so an individual animal can do considerable damage once it establishes a territory near an agricultural field or backyard garden.

Another trait that does little to endear groundhogs to most landowners is their ability for digging burrows. A single groundhog can excavate about 35 cubic feet of dirt weighing almost 700 pounds for its underground home. A typical groundhog burrow will comprise more than 40 feet of tunnels as deep as five feet with from two to five separate entrances. These extensive underground tunnel systems can undermine building foundations and often collapse under the weight of farm machinery causing damage to the equipment and potential injury to the operator. While the groundhog’s affinity for digging tunnels does nothing to endear it to humans, many animals benefit from those labors. Rabbits, skunks, raccoons and even foxes that are not as skilled at underground excavation will readily use abandoned groundhog burrows for shelter or as a den.

Although most of a groundhog’s lifestyle does little more than put it firmly into the varmint category, this large rodent is a perfect model of the remarkable biological process known as hibernation. Groundhogs are true hibernators that spend the winter in a state of deep sleep and decreased metabolic activity.

The body temperature of a hibernating groundhog can drop from a normal of 90 degrees to somewhere in the low 40s. Its breathing also slows dramatically, and its heartbeat will decrease from nearly 100 beats per minute to a mere 4 beats per minute. This complete slowdown of bodily functions allows the animal to conserve vital energy by maintaining this dormant state. Groundhogs spend the winter in hibernation not to escape the harsh weather but rather because their food sources are nearly nonexistent.

Groundhogs often build a special winter burrow well below the frost line for hibernating. In our area, most groundhogs will go into hibernation by late October or early November, about the time the first killing frosts eliminate the last of their food sources for the year. They generally emerge from their winter sleep again in late March or early April when the greenery they eat starts to grow again. This post-hibernation period is also the breeding season. Unlike most rodents, however, groundhogs are not that prolific, having just one litter of two to six pups per year. The young are born after a gestation period of 31 or 32 days, and they will be weaned and on their own after five to six weeks. That’s probably why the carcasses of road-killed groundhogs become a common sight on rural highways in late May and early June.

So armed with a little real-world knowledge of the life and times of the overgrown ground squirrel we call the groundhog, I’m still scratching my head as to how a critter that nature has destined to never see a day of winter has come to be regarded as the paradigm of weather prediction.