Groundhogs (also known as woodchucks), medium- to large-sized rodents in the Sciuridae family, are a common intruder in many backyards and homes. Spring, summer, and fall months are the times when groundhogs are most likely to cause mayhem on your property. Yet, they seem to disappear during the winter months. So, do groundhogs hibernate? Yes. Groundhogs seek shelter in underground dens from October through February and this timing depends on geographic location (shorter duration of hibernation in southern, more temperate locations). During hibernation, their breathing and heart rate is decreased and they can lose more than half of their body weight. While hibernation might sound simple, there’s more than meets the eye. Here are some groundhog hibernation facts you should know.
History of Groundhog Day
Groundhog Day falls on February 2nd each year. While this date is approximately the midpoint between winter and spring, it is also the time when groundhogs start arising e from hibernation in some regions. Each year, many locations in the United States and Canada celebrate Groundhog Day; however, Punxsutawney, Pennsylvania may have the largest known celebration. Spectators watch groundhogs emerge from their burrows. Tradition suggests that, if the groundhog sees its shadow, it will go back into its burrow and there will be another six weeks of winter. If a shadow is not observed, then spring temperatures are just around the corner. This tradition began when Germans first settled in Pennsylvania. How successful have these animals been at predicting the forecast? Not great. Groundhogs have barely proven a 50% success rate in weather prediction. Thus, you shouldn’t depend on groundhogs in your backyard to clue you into weather patterns.
During hibernation, groundhogs live in underground burrows that they dig (you may observe piles of dirt near the den opening). Throughout the winter, they are inactive, their heart rates slow and their body temperatures drop to approximately 39-40 degrees Fahrenheit.
So, exactly when do groundhogs hibernate? This is a several-month process extending from late October to early February, depending on their geographic location. For example, Maine groundhogs hibernate for approximately 175 days whereas those in South Carolina may only hibernate for 67 days.
Toward the end of the hibernation period, males emerge first and will often join females in their burrows. This marks the beginning of mating season as males begin to explore mating options. Mating does not occur until emergence in the spring. Yet, this preemptive activity helps groundhogs build bonds and establish territories in preparation of the upcoming season.
Groundhogs do not eat during hibernation. They spend the fall months (prior to hibernation) feeding on protein-heavy, rich foods to build fat reserves. Groundhogs are herbivores and eat grasses, other plants, berries, grains, and nuts; however, they occasionally eat other foods such as insects (e.g., grasshoppers) or other small animals. Their fat reserves must last them throughout the winter. Thus, fall is one period when your backyard is prone to attack from groundhogs, as well as spring when hungry groundhogs emerge from hibernation.
Groundhogs may have evolved to hibernate due to their dietary needs. During winter months in some regions, food is usually scarce and harder for groundhogs to find. Hence, groundhogs' metabolism and appetite hormones may have adapted to down regulate production in association with cold weather. Conversely, warmer weather may trigger metabolism and appetite cues that help groundhogs know when to wake up and start searching for food again.
Identification and Potential Removal
While groundhog hibernation can give you momentary peace from these potential backyard pests, activity begins again in the spring. To keep the peace on your property, consider scheduling an appointment with Terminix®. Our trained technicians can help to put your groundhog problems to bed for good.