Woolly bear caterpillars, or woolly worms, are a common sight this time of year as they begin to seek out a safe place to ride out the upcoming winter.
But, could they also be trying to give us a heads-up about what the approaching winter holds for us?
According to a well-known legend, they just might.
A woolly bear caterpillar’s body is made up of 13 segments, colored either black or brown. If there’s more brown, legend has it that the upcoming winter will be milder. More black coloring suggests a harsher winter ahead.
So, let’s take a look back at how the legend started. In the fall of 1948, Dr. C. H. Curran from the American Museum of Natural History in New York traveled to Bear Mountain, outside of New York City, to study the caterpillars there.
By determining the average number of brown segments in the caterpillars over the next 8 years, each fall Curran found more than a third of the caterpillar’s bodies were colored brown. And yes, the following winters were milder than normal.
But is it really that simple? TV5 went to the Chippewa Nature Center in Midland to learn more.
“These guys are looking for cover. They’re going to be spending the winter down in the leaf litter in people’s gardens, back yards, out among the plants,” explained Jenn Kirts, who is the Chippewa Nature Center's Director of Programs.
Kirts said the caterpillars can freeze during the winter, but in the spring, they create a cocoon and emerge as an Isabella Tiger moth.
“From there, those moths will mate and have eggs that will hatch in May. And they go through the whole life cycle all over again,” said Kirts.
But what about the legend? Can the caterpillars really predict the upcoming winter?
“Like all cold-blooded animals, the weather does have an impact on their development. But the color of their bands has more to do with their history, what conditions were like as they’ve been growing up, than it does as a prediction,” explained Kirts.
So, a slight weather correlation, just not a prediction.