July 15, 2024

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Woolly Bears and the Winter Weather

I’m sure you’ve heard the old wives tale about the Woolly Bear caterpillars ability to predict the winter weather. The wider the brown middle band is, the milder the winter. Well, since I didn’t have any immediate plans for the  weekend I decided I may as well startwoollybowl25 my own study and see just how accurate a Woolly Bear can be. Really I just love projects and this sounded kind of fun and it gave me an excuse to go outdoors. I grabbed an old cool whip container and the hunt was on. Finding Woolly Bears in the Fall really isn’t a tough task, the best places to look are around rocks, rock walls, flower gardens and sidewalks.  My goal was to collect 25 Woolly Bears and measure their mid sections as well as the black bands on their head and tail. If they were to predict a mild winter then the middle brown or sometimes orange/brown band would have to be at least half the body length. The average body length of a Woolly Bear in a relaxed resting position is 1 1/2 inches long. That means we would need to get an average length of 3/4 of an inch or more on the brown band on our collection. Lets see what our measurements added up to.

Average black head band length – 0.44 inches or about 7/16ths of  an inch.

Average black tail band length –  0.325 inches or about 5/16ths of an inch

Average brown middle band length – 0.645 inches or about 5/8ths of an inch

measure1Judging by the figures above according to the Woolly Bear folklore we should be in for a harsh winter.    Damn! and here I was hoping for a mild one.  The interesting thing about those averages is that there were 8 specimens that measured 3/4 of an inch or more in length. Subjects #10 and #14 both measured a full inch long at the mid section, nearly twice as long as the majority of our caterpillars. Most of our caterpillars, 10 total, measured a solid 1/2 inch long at the mid section.


Not to get discouraged (after all I want a mild winter) I set out the next day to collect as many Woolly Bears as I could find in 30 minutes. This time I would count the brown segments and approach it from that angle. I managed to round up 28 caterpillars. Yes, some could have been the same ones as the day before but who could tell, they all look alike.  A Woolly Bears body has 13 distinct segments to it.  Technically we would need to find that 7 segments were brown to predict a mild winter, it wasn’t looking good.

Average black head segments – 4.678 2woollybears

Average black tail segments – 3.25

Average brown segments – 5.035

I really shouldn’t have included specimen #17 because he had only 2 black head segments no black tail segment and a whopping 11 brown segments. If I hadn’t included him our average brown segments would have been closer to four.  Nearly half, 12 of our caterpillars had only 4 brown segments.  There were a total of eight subjects that had 6 brown body segments. All this again according to folklore points toward a hard winter.  (Insert sad face here.)

Some interesting things I learned with my little study:

  • Woolly Bears crap a lot and you’d be surprised at just how big a poop a little caterpillar can do.
  • No matter how hard you try you can’t get a Woolly Bear to uncurl with your finger.
  • You can however get a Woolly Bear to uncurl by placing in him in your cupped hand, cup over that hand with your other one and gently blow long breaths into your hands. Usually by four long breaths you’ll feel the caterpillar start to move. woollypoop
  • Woolly bears crap a lot. Did I say that already?

We’ve already got our calendar marked for next year to do another little study. We’ll find out shortly if the Woolly Bear is right and the winter of 2013-2014 is a harsh one and if they really can predict the winter weather.

Stay tuned!


 Update 1/30/2014

I chose that nice blue color to match the temperatures outside…… it is FREEZING!!  I don’t remember a colder winter than this one. We’ve had some significant snowfall early in the season and then a lot of freezing rain and a lot of below zero days. So the score on the first year of our study is 1 zip. The Woolly Bears have this winter correct, harsh no doubt.

Update 4/22/2014

Believe it or not the snow just melted, winters here in the Adirondacks seem to last forever. Those caterpillars sure had this winter pegged. It was long, it was cold, it was snowy!!