Groundhog Day All Over Again

By Jim White, Associate Director, Land and Biodiversity

Well, Groundhog Day has come and gone.  And a special day it was indeed. It’s the only day of the year that we humans disregard modern computer forecasting, satellite monitoring, and hype–prone weather men and women and put our faith a furry marmot to predict our weather.  Each year on February 2ndin Punxsutawney, PA  with great pomp and circumstance, a captive groundhog is pulled out of his cage. If he “sees” his shadow (the sun is out) there will be six more weeks of winter and if there is no shadow (it’s cloudy) spring is right around the corner.  This year the official groundhog, better known as Punxsutawney Phil, saw his shadow and I quickly booked a flight to Florida (just kidding).

Punxsutawney Phil looks for his shadow.  Photo from
Punxsutawney Phil looks for his shadow. Photo from

Apparently this weather-predicting-mammal custom was imported from Germany where it is said that farmers would watch hedgehogs as they emerged from hibernation. As with our native groundhog, the hedgehog would retreat back into its burrow if it was sunny and remain out if clouds blocked the sun.  The farmers somehow correlated this behavior with the length of remaining winter weather.  You may or may not put much faith in this unconventional forecasting method but it seems that many of us are at least somewhat interested in Phil’s prediction.  It was reported that on February 2nd 2010, the official website of Punxsutawney Phil received 6.5 million hits (a few more than this blog typically gets.)

Weather forecasting aside, I think the Groundhog (Marmota monax) is a very interesting mammal. It is one of the few mammals in our area that truly hibernates in winter. In the fall, Groundhogs increase their food intake and increase body fat. This, and the ability to conserve energy by eliminating movement and reducing their body metabolism and internal temperature (to as low as 40 degrees), enables them to survive the winter underground in their burrow.

The main entrance of a Groundhog burrow.  Photo by Jim White.
The main entrance of a Groundhog burrow. Photo by Jim White.

Also, Groundhogs are one of the easiest animals to observe in our area because they commonly live in open fields, wood edges, and under human structures. Their burrows are dug as much as six feet deep into the ground and can have several chambers that are used for refuge, rearing young, or hibernating. They usually have more than one burrow and each burrow usually has two entrances:  a main entrance and a second “bolt” hole that can be used to escape predators. Groundhogs are very common throughout the non-mountainous areas of the northeastern and central United States.  I’d be surprised if anyone reading this blog had never seen a Groundhog!

A Groundhog surveys his real estate during the summer.  Photo by Jim White.
A Groundhog surveys her real estate during the summer. Photo by Jim White.

Despite the “hog” in their common name, Groundhogs are not closely related to pigs. Groundhogs are members of the squirrel family (Sciuridae) within the order Rodentia (rodents; or gnawing animals).  Like all rodents, Groundhogs are vegetarians and have one pair of upper incisors (the chisel-shaped teeth at the front of the mouth), and one pair of lower incisors.  Groundhogs consume large quantities of grasses and broadleaved vegetation and love nothing better than to raid vegetable gardens.  This latter trait and the fact that Groundhog holes in fields pose more than a little danger to livestock combine to make the Groundhog one of the least loved of our native mammals.

A little known fact about Groundhogs is that they can also climb trees.  Although they are primarily ground dwelling, I’ve seen them as much as ten feet up in the branches of trees munching on leaves.

Another common name for the Groundhog is “Woodchuck” (although to set the record straight, Woodchucks really can NOT chuck wood); but my favorite name by far is “whistle-pig”.  “Whistle-pig” refers to the whistling sound that Groundhogs make as an alarm call when threatened.  Other vocalizations include barking and hissing

So whether you do or don’t like these chubby, voracious creatures and whether or not you are a believer or non-believer in their forecasting ability, I think you have to admire Groundhogs for their sheer ability to adapt and thrive in our region.

For a different type of wildlife experience, join us on the Wastewater Treatment Tour and Birding program on Tuesday, February 9, 9:30 a.m. to noon.  Tour the Wilmington Wastewater Treatment Plant to see what happens to our water once it goes down the drain.  Look for ducks and other birds on the large settling ponds overlooking the Delaware River.

4 thoughts on “Groundhog Day All Over Again”

  1. Thank you so much for this great article. I learned quite a lot about groundhogs. I wasn’t aware that they could climb tress. The mention of tree climbing reminded me of a groundhog I observed in our neighbor’s yard. The groundhog was under their plum tree and would stand and stretch to his full height to pick the plums from the lowest hanging branches. Some of our friends thinks we’re kind of crazy because we know where some groundhogs live in our area and periodically we “visit” them to see how they’re doing! Groundhogs are awesome! Thanks again for this article.

  2. I enjoyed your article. Yes! Groundhogs are interesting and fun to watch, but they are not appreciated by horse owners! Too bad they don’t “nest” in the trees instead of making holes in our fields…

  3. And groundhogs especially love amaryllis plants and bulbs. I have put the plants out for summer only to have the groundhogs pull the bulbs out of the pots and drag them away to their burrow. I put the pots up on the deck thinking that would be high enough….no problem, our resident groundhogs just came right up the stairs and again took the bulbs right out of the pots..left their tracks in the dirt they spilled. Since then, I have kept the plants in the sun room. They still eat the hosta and other plants in the flower beds and raid the bird feeders and give us great pleasure when we catch a glimpse of babies skittering across the yard.

  4. Hey Marilyn! Riding in the Laurels one day, we ‘chased’ a groundhog up a tree; they look really funny clinging to the side of a tree!

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