Groundhogs and Shadowy Doings
The groundhog (Marmota monax) -- also known as the woodchuck, the land-beaver, and the whistle-pig (probably because of the sound they make when alarmed) -- is the largest member of the squirrel family.
But, whatever it's called, can it accurately predict the weather on Feb. 2 or any other day?
No. Well, sort of.
According to researchers at Cornell, groundhogs, who hibernate during the winter, may start getting hormonal twinges at this time of the year as it becomes light for more hours of the day. Just like humans, their bodies produce melatonin, a hormone in the brain that determines a body's internal clock (including when to sleep and when to wake up). Because exposure to light causes melatonin production to fall off, it being lighter longer may alert the groundhog's brain that it should start waking up.
So a groundhog can't actually tell whether it's going to be cold or warm, snow, or have blue skies throughout February and early March based on whether it sees its shadow or not. But it can tell you that the days are staying light longer. After all, Feb. 2 is roughly halfway between the winter solstice and the spring equinox, and much of the United States has ten hours of sunlight a day at this time of the year.
Oh, and don't just take our word for it. Statisticians have counted and it turns out that groundhogs are accurate with their predictions roughly 39% of the time.
So, the groundhog's predictions on Feb. 2 don't really impact the arrival of spring, but it can help raise some great conversations about shadows and what they do mean. Here are some lessons to help:
- Sky 2: Shadows (K-2)
- Sky 3: Modeling Shadows (K-2)
- Cooler in the Shadows (K-2)
- Measuring Shadows (6-8)
How can Groundhog Day become an educational experience for students? (Thinkfinity Community discussion)