Ask a Naturalist: Is a groundhog’s shadow a harbinger of spring?

(Photo by Barbara L. Hanson)

Almost all animals made of more than one cell have symbolic, mythic, shamanic meanings and resonances in the cultures of the world. Many, like birds, are believed to tell the future. Few have so precise an oracular calling as a single annual instance of predictive meteorology. While Groundhog Day was first celebrated in 1887 (in Punxsutawney, Pennsylvania, famously), the myth finds its origins in the Christian holyday of Candlemas: a combination of superstition and common sense by which the length of winter was measured and calculated in candles. The Germans were the first to associate the ritual with the groundhog, developing the curious myth that we all know: If the groundhog emerges from its hole and sees its shadow, it becomes frightened and retreats back into the hole, prophesying six more weeks of harsh winter. If it sees no shadow, the way is cleared for an early spring.

First described in 1758 by the Swedish scientist Carl Linnaeus, the groundhog is a well-known character in the Hudson Valley – a bane of farmers, but an awful lot of fun to observe, with their vast networks of holes and tunnels and their odd composure as they appear to stand or sit erect by the side of the road, eating an apple in a vaguely humanoid way.

Multiple names and odd myths aside, they are rather literally shrouded in mystery, as much as their essential life functions happen underground. We caught up with Elizabeth Long, PhD – director of Conservation Science at the Mohonk Preserve and one of our most knowledgeable and expressive go-to experts in the Ask a Naturalist series – to shed a little light underground and help us understand more about the curious rodent we celebrate for its prophetic powers each February 2.


Groundhog or woodchuck?

Both! I grew up in southwestern Virginia, where we typically use the word “groundhog” to describe these large rodents. Since moving to the mid-Hudson Valley, I’ve noticed that locals are more apt to use “woodchuck” when talking about the animals that the Linnaeus called Marmota monax in 1758.

Groundhog makes sense; it’s a kind of hoglike thing, and it’s in the ground. What, however, is the exact nature of their relationship with wood?

Despite the name, woodchucks don’t “chuck” anything, nor do they eat wood. The term seems to have come into English usage via Native American speakers who referred to them as wuchak. Another colloquialism, “whistlepig,” refers to the alarm call that they make when startled by predators or other perceived dangers.

Hog, pig…that’s an awful lot of porcine descriptors for a rodent. I’d like to add “tunnel boar” and see if it catches on, okay? Anyway, if they don’t eat wood, what exactly do they eat?

Mostly plants. Their typical diet is heavy on grasses, wild berries or scavenged garden or farm vegetables. Like many “vegetarian” animals, though, they will eat meat if they get the opportunity. Insects and other small invertebrates are common foods, and they will even eat small ground-nesting mammals or birds if they get the opportunity.

I lived in an apple orchard for five years at one time and developed quite a fascinating relationship with the community of groundhogs that lived around – and under – my house. My landlords, however – apple farmers – had a much less kindly attitude toward them. Their complex tunnel networks can cause quite a bit of damage to property, farm vehicles and structures. Is it possible to get a groundhog out from, say, under a shed? For its own good as well as the shed’s?

Groundhogs typically live solitarily in a single burrow with multiple entrances. In our area, these burrows can get quite deep, as the animals seek to get below the winter frostline. While they’re unlikely to undermine your foundation in the short term, a burrow-and-tunnel system that has been in use for many years can eventually start to make the ground unstable.  And yes, they have also been known to cause a lot of damage to vehicles and yard and farm equipment.

The first step to getting them out of your yard is to make the area unfriendly to them. Remove plants, wood, rocks or other substrate that they can use as cover. If you know there are abandoned burrows around, use heavy gravel to fill them in. Use a humane trap – or have a wildlife removal specialist do it for you – to live-trap the animal and relocate it. Be extremely careful! Wear gloves, and do not attempt to handle the animal. Groundhogs are rodents, which means they have extremely strong, sharp teeth and are capable of causing tremendous damage with their bite. They can also carry and transmit diseases or parasites, so clean the area and your clothing very well after you are done.

Some people have had luck applying repellants, such as cayenne pepper mixtures, into burrows once the animal is removed.

Okay, I have held my tongue long enough and can no longer hold off on the marquee question burning in our readers’ minds: Is it true, or in any way a scientifically comprehensible myth, that if a groundhog sees its shadow we’ll have a long winter, and if it doesn’t, we’ll have an early spring?

While groundhogs are impressive animals that are very well-adapted to changes in weather, sadly, they can’t tell us much about the future weather. Groundhogs spend most of the winter in their burrows, hibernating. Their metabolism slows down dramatically and their physiological processes – heart rate, circulation, breathing – go into “sleep mode,” just active enough to keep the animal alive. The deep burrow that a groundhog uses should keep the temperature fairly constant for the whole winter. While hibernating, the animal’s fat supply functions as energy. When they emerge from the burrow in early spring, they have very little fat left and must quickly begin to locate food to replenish their stores.


Yes. No.