'Wisdom' of Woolly Bear Weathermen is Called into Question

The expert recently wrote on the subject in The Conversation, saying that "there is little reliable or repeatable evidence linking the severity of winter with the breadth of the woolly's stripe."

However, when invesitgators sought to detemine what led to the variability in brown stripe length from year-to-year, they found out they can actually tell us about the weather.

"Unfortunately," Coppinger added, "it was the weather last spring."

Each year, when spring rolls around and the ground thaws, the woolly bears miraculously wake from their chilled slumber to start building a chrysalis and begin pupation. Weeks later, the incredibly fuzzy caterpillar emerges as a beautiful, and equally fuzzy moth.

In a week's time, these nocturnal moths mate, lay eggs, and die, and soon new woolly bear caterpillars are born.

According to Coppinger, as a woolly bear ages, its center segments grow longer and larger, resulting in more brown hairs on its body. In that sense, the oldest and fattest of these worms will almost always be the brownest, born during a warm spring with an early thaw.

Still, the expert acknowledges that this explanation is not nearly as mysterious nor exciting as a good legend.

"It's hard to let go of beloved folklore" he added. "Personally, I love cold, harsh, snowy winters. While I no longer believe that caterpillars can predict the weather, I still can't help smile when I find an all-black woolly bear caterpillar."

Coppinger goes on to banish illusions about a few other folk wisdoms, and if you can handle the truth, you can read about them at The Conversation.

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