February 2, 2013

The Science of Groundhog Day

by Christine Hoekenga

A Groundhog on Green Grass

The subject of much folklore, groundhogs (also known as woodchucks), are members of the same family as squirrels and marmots.  Image courtesy: Jonathan Crowe (Flickr CC)

Ah, Groundhog Day. That whimsical winter moment when even the most logical among us pause to embrace the silly, hopeful notion that a rodent can predict the coming of spring.  In case you haven’t heard the news, Punxsutawney Phil (the standard-bearer among groundhogs) emerged from his burrow this morning at 7:52 am Eastern and did not see his shadow, indicating that “spring is near.’ (Had he seen his shadow–as he has 100 our 117 years on record–he would have predicted six more weeks of winter.)

It’s true that there’s probably not a lot of science in the air when the revelers and TV cameras gather at Gobbler’s Nob each year on February 2nd to watch Phil, North America’s most famous meteorological marmot, look for his shadow and make his prediction.  But there is plenty of interesting science related to groundhogs as a species and even to the tradition of Groundhog Day itself:

Earth Science and Astronomy
The tradition of Groundhog Day in North America dates back to at least 1887 and likely has its roots in an old European celebration called Candlemas Day.  The date itself, February 2nd, is one of four “cross-quarter days” or dates on the calendar that fall halfway between a solstice and an equinox. Celestially speaking, Groundhog Day is halfway between the beginning or winter and the beginning of spring–a logical time to consider how many more weeks of cold weather are coming.

Meteorology and Statistics
NOAA’s National Climatic Data Center has analyzed the accuracy of Phil’s predictions (based on monthly average temperatures for February and March) each year since 1988.  They’ve determined that Phil, while cute, has “no predictive skill…during the most recent years of his analysis.”

Groundhogs (known to biologists as Marmota monax), are related to squirrels and other marmots. They are burrowing animals (though they also have limited climbing and swimming abilities) and are among the animal kingdom’s true hibernators. During hibernation, which typically lasts until early February (depending on the latitude), a groundhog’s heartbeat slows from 80 beats per minute to about five beats per minute and body temperature drops from 98 degrees Fahrenheit to as low as 38 degrees. These dramatic biological rhythms have made groundhogs a model subject for medical research on topics including circadian rhythms, mental health, cancer, blood cell function, and liver disease.

Read the full special report on Groundhog Day from NOAA’s National Climatic Data Center.

While Punxsutawney Phil may not be a shining example, see how human meteorologists have made great strides in recent decades in using science to forecast weather conditions.

Learn how one researcher at Cornell University, Patrick W. Concannon, is using groundhogs to better understand the human endocrine system and liver disease.

Christine Hoekenga

Written by

Christine is a freelance writer, editor, and content strategist, specializing in science and nature. She holds an Bachelor's degree in Environmental Science and Media Studies and a Master's of Science Writing. She has been working in science communication and education for nearly a decade as a journalist, an organizer for conservation groups, and a museum educator. Before joining the Visionlearning team, she served as the New Media and Online Community Manager for the Webby award-winning Smithsonian Ocean Portal. Christine is assisting Visionlearning with developing new modules and glossary terms, managing the blog, and outreach through social media.