Wildlife expert Michael Runtz, who has been observing groundhogs for pretty much his entire life, calls them a fantastic species. “They have lots of interesting behaviours and adaptations. For one, they are the world’s largest hibernating animal.” 

Though many assume bears are our heftiest hibernators, they actually don’t truly hibernate. To be a true hibernator, an animal has to have a body core temperature that drops to only a few degrees above freezing and a heart rate of fewer than eight beats per minute. “On the groundhog, it’s about five beats per minute. That’s almost a deathlike state to survive the long winters that they experience up here.”

One of Canada’s most highly respected naturalists, nature photographers and natural history authors, Runtz lives and breathes nature. A lifelong naturalist, he began birdwatching at the age of five. He has authored more than a dozen books on topics ranging from beavers and wolves to wildflowers and the seasons of Algonquin Park. He currently works as a lecturer at Carleton University in Ottawa, teaching natural history.

Groundhog Day dates back to early Christianity with the tradition of Candlemas, also known as the Feast of the Presentation of Jesus Christ, which was celebrated on Feb. 2. “This evolved into the belief that if it was sunny on Candlemas day, there’d be another couple months of winter, going into May,” says Runtz. 

This belief was then expanded by the Germans, who introduced an animal, the hedgehog, to appear on Candlemas day. “If the hedgehog appeared and saw its shadow, which of course, reflects the fact that it would be sunny, that would mean winter would go into May.” Runtz explains that when Germans came to settle North America, they brought the belief about Candlemas day and the hedgehog with them. “But of course, we don’t have hedgehogs here, so the groundhog was the perfect animal to replace it.”