10/22/09 Woolly Bear Season. Do They Predict the Weather?

A true sign of fall yesterday at the Smith house.                Our exchange student, Milou brought a “cute” black and brown caterpillar into the house and after close inspection, it turns out that it was a woolly bear! I told her these little guys can predict how severe the winter will be. Naturally she asked, “will it be as bad  as the winters in Holland?” Well no, but is there any truth to predicting with these little guys?  

According to The Farmer’s Almanac:

  How the Woolly Bear Became "Famous"

• In the fall of 1948, Dr. C. H. Curran, curator of insects at the American Museum of Natural History in New York City, took his wife 40 miles north of the city to Bear Mountain State Park to look at woolly bear caterpillars.
• Dr. Curran collected as many caterpillars as he could in a day, determined the average number of reddish-brown segments, and forecast the coming winter weather through a reporter friend at The New York Herald Tribune.
• Dr. Curran's experiment, which he continued over the next eight years, attempted to prove scientifically a weather rule of thumb that was as old as the hills around Bear Mountain. The resulting publicity made the woolly bear the most recognizable caterpillar in North America.

    Do Woolly Bear Caterpillars Forecast Winter    Weather?

According to legend, the wider that middle brown section is (i.e., the more brown segments there are), the milder the coming winter will be. Conversely, a narrow brown band is said to predict a harsh winter. But is it true?

• Between 1948 and 1956, Dr. Curran's average brown-segment counts ranged from 5.3 to 5.6 out of the 13-segment total, meaning that the brown band took up more than a third of the woolly bear's body. As those relatively high numbers suggested, the corresponding winters were milder than average.
• But Curran was under no scientific illusion: He knew that his data samples were small. Although the experiments popularized and, to some people, legitimized folklore, they were simply an excuse for having fun. Curran, his wife, and their group of friends escaped the city to see the foliage each fall, calling themselves The Original Society of the Friends of the Woolly Bear.

Mike Peters, an entomologist at the University of Massachusetts, doesn't disagree, but he says there could, in fact, be a link between winter severity and the brown band of a woolly bear caterpillar. "There's evidence," he says, "that the number of brown hairs has to do with the age of the caterpillar—in other words, how late it got going in the spring. The [band] does say something about a heavy winter or an early spring. The only thing is . . . it's telling you about the previous year."

Read the full article here…

Below is the one Milou found. Looks like the brown is fairly wide. Mild winter?

By the way...they have a festival every year, this year was their 32nd!!!

What do you think?

See you soon,

Brian