Happy Groundhog Day! Today is the day when we eagerly (some more than others) await whether the groundhog in Punxsutawney, PA, will see his shadow or not. The superstition goes that if “Phil” does, there will be 6 more weeks of winter. Apparently Phil did see his shadow this year, so spring is still a little ways off. But what the heck is a groundhog anyway? If you live in the western U.S., including Colorado, and/or you’ve never seen the Bill Murray movie Groundhog Day, you may have never seen one. And what makes a groundhog different from that more ubiquitous western rodent the prairie dog?
As I’ve already given away, both groundhogs and prairie dogs are rodents, which means that, like mice, they have continually growing front teeth that they must constantly wear down by gnawing. They also share the same family: Sciuridae. This group of rodents includes squirrels and chipmunks.
The names “groundhog” or, its other common name, “woodchuck,” are pretty vague, but the animal’s taxonomic name may give a better clue as to what sort of animal we’re looking at: Marmota monax. The groundhog is a type of marmot, very similar in fact to the yellow-bellied marmot that makes its home at high elevations in places like Rocky Mountain National Park. Unlike the yellow-bellied marmot though, the groundhog is a flat-lander. Back in Virginia, I often saw them foraging in the summer on the grassy side of the road.
Like the prairie dog, three species (Cynomys gunnisoni, Cynomys leucurus, and Cynomys ludovicianus) of which make their home in Colorado, groundhogs are diurnal (active during the day) and live in burrows, but the groundhog lives either alone or with a small group of family members rather than in the large towns that prairie dogs inhabit. They’re also bigger (up to 26 inches long and 9 lbs) than their relatively svelte cousins (up to 16 inches long and 3 lbs) and are more omnivorous, eating more insects along with seeds and grasses.
One of the biggest differences between the groundhog and the prairie dog, however, is that the prairie dog is considered a keystone species. A keystone is the stone in an arch that, when pulled out, causes the rest of the stones to fall. Therefore, a keystone species is one that, when removed from an ecosystem, causes that ecosystem to collapse. By virtue of their incredible tunneling skills, prairie dogs provide homes for animals as diverse as burrowing owls, rattlesnakes, and cottontail rabbits. Their abundance, and the fact that they don’t hibernate during the winter like groundhogs do, means that they provide a stable, year-long food source for many other animals as well, such as coyotes, hawks, and the endangered black-footed ferret. Recent studies have also shown that prairie dogs help prevent erosion, decrease soil compaction, and encourage the growth of grasses and forbs that large grazers such as bison and pronghorn tend to prefer.
Sadly, the chief skill groundhogs and prairie dogs have in common–digging–is also what puts them at odds with people. There are numerous pest control companies tasked with removing groundhogs from people’s lawns. Even worse has been the wide-scale eradication campaign against the prairie dog since the early twentieth century due to fears that prairie dogs compete with livestock for forage or that stepping in prairie dog burrows causes injuries to livestock.
Given their benefit to the prairie community, perhaps the prairie dog needs to take a page from their cousin the groundhog and come up with a better PR campaign. Maybe starting with an official Prairie Dog Day?