The groundhog (Marmota monax), also known as whistle-pig (because it makes a high-pitched whistle sound when warning others of danger), woodchuck and land-beaver, is a rodent belonging to the Sciuridae family, the same family with chipmunks and squirrels.
The length and weight of an average groundhog is 17-26 inches (including its bushy tail) and 4.5-9 pounds. Some have been known to be as big as 32 inches and 30 pounds. They have two layers of fur. The inner layer helps them hold in body heat and the outer layer serves as a waterproofing layer. They also have powerful limbs and thick claws, making them excellent diggers.
Groundhogs in the wild live about 2-3 years. In captivity, they can live much longer. Wiarton Willie (the well-known Canadian groundhog who was part of the Groundhog Day celebrations in Wiarton, Ontario) lived to be 22 years old before he passed away in 1999.
The groundhog lives in North America, most commonly in the northeastern and central parts of the US. They prefer woodlands that meet open spaces, such as fields and streams. They are mostly seen on the ground but they can climb trees (to survey their surroundings and escape predators) and they are capable of swimming.
Groundhogs sleep, raise their young and hibernate in burrows. A very interesting fact about the groundhog is it can remove an estimated 700 pounds of dirt when digging a burrow. The tunnels can be up to 5 feet deep and up to 45 feet in distance. They normally consist of 2-5 entrances, thus giving them a better chance of escaping in case a predator was to enter.
Groundhogs are mostly herbivorous. They primarily eat grass and other vegetation, including clover, dandelion greens and alfalfa. They also eat nuts, insects, snails and agricultural crops.
During the summer time, groundhogs binge to purposely put on a lot of weight to prepare themselves for hibernation.
Groundhogs are one of the few animals to truly hibernate. Normally after the first frost (about October), they will retreat to their burrow in the deepest part below the frost line where temperatures stay above freezing. In order for them to survive the winter, groundhogs can greatly reduce their metabolism.
Their body temperature decreases from about 99° F to about 40° F, their heart rate decreases from about 80 beats per minute (bpm) to about 5 bpm and their respirations decrease from about 12 per minute to about 4 per minute. This allows them to consume less energy so they can live off of their stored body fat for a few months. By the time hibernation is over, they can lose about half of their body weight.
After hibernation, breeding season begins. The male and female pair stay in the same den throughout the gestation period (about 28-32 days). When the young are about to be born, the male will leave. The female will give birth to 2-6 blind and hairless babies. In 5-6 weeks, they are weaned and ready to seek their own dens.
About Groundhog Day
Groundhog Day is celebrated on February 2 in the US and Canada. According to folklore, on this day the groundhog emerges from the burrow to predict the weather. Winter will end soon if the groundhog does not see its shadow and it will last another six weeks if it does see its shadow.
The very first Groundhog Day was celebrated in Punxsutawney, PA in 1886. The first official groundhog was Punxsutawney Phil. Some claim a 75-90% accuracy in the groundhog’s prediction. However, according to a Canadian study, the success rate is more like 37% (based on 13 cities over the past 30-40 years).
In 1993, the movie Groundhog Day, starring Bill Murray, brought worldwide attention to this most-watched weather forecast day led by a rodent.