Category Archives: Nature Notes

Why Did the Woolly Bear Cross the Road?

Posted on November 12, 2014 by Kristin S.

Fall brings with it the familiar and well-loved sight of woolly bear caterpillars crossing roadways and sidewalks. Looking like orange and black-banded bottle brushes, these 1-2 inch caterpillars dodge vehicles and bicycles to get to the other side.

With luck and time, these beloved caterpillars will transform into Isabella Tiger Moths, a yellowish-brown moth not nearly as cute as its immature form.

 

Woollys in Winter

Woolly bears are one of the few caterpillars to overwinter as caterpillars, risking freezing temperatures and predation to emerge in the spring. Quite simply, woolly bears crossing roadways are risking life and legs to find the perfect leaf litter, the perfect board, or the perfect pile of wood chips under which to hibernate. They need a spot sheltered from drying winds, a bit of moisture, and cover from predators.

When they find that spot, they curl up in a tight ball and settle in for a long winter. Their bristle hairs are a deterrent to predators (although raccoons have been observed brushing the hairs off and then eating these insect delicacies). The spiky ball shape makes the caterpillars slippery to predators. If you try to pick up a woolly bear in its hibernating pose, you may find it slips from your grasp.

Woolly Bear

Come Springtime

If a woolly bear survives a New England winter, it will emerge in the spring very hungry. At this time of year, you may see caterpillars wandering again as they search for food plants. The caterpillar eats for a short while and then spins a cocoon, made of bristle hairs held together with silk, in a protected spot under rocks or bark. In two weeks, an Isabella Tiger Moth emerges from the cocoon.

The cycle begins again when the female Isabella Tiger Moth lays clusters of eggs on a variety of hostplants. Favorites include dandelion, grass, meadowsweet, nettle, and more. Eggs hatch in 4-5 days, and the young caterpillars feed in groups, becoming solitary as they grow older. Over 3-4 weeks, the caterpillars undergo 6 molts, or skin sheddings, and it is the second generation each summer that will cross roads to find that perfect overwintering spot.

Fun Facts about Woolly Bears

  1. Woolly bears are very fast (for a caterpillar, at least). They can travel up to 4 feet per minute, which is roughly equivalent to .05 miles per hour.
  2. Contrary to folklore, the woolly bear is not an accurate weather forecaster. Does the width of its orange band predict the severity of the oncoming winter? No. Instead, each time the caterpillar sheds a skin, its orange band grows a bit larger. So, broader orange bands are most likely an indication of the age of the caterpillar, not of future winter weather.
  3. Banner Elk, North Carolina has been celebrating the Woolly Worm Festival since 1978. During the “Woolly Worm Race,” pet woolly bears race up a 3 foot long string. The winner becomes the official predictor of winter.
Red Fox

Fox or Coyote? How to Tell Them Apart

Posted on October 29, 2014 by Rosemary

Most of us only ever catch fleeting glimpses of coyotes or foxes, and these brief encounters can leave us wondering what species we saw. Besides the domestic dog, our state hosts three members of the family Canidae, a word that comes from the Latin word for dog, “canis.” Here’s a primer on wild canines in the Commonwealth.

Red fox (Vulpes vulpes)

(c) Colleen Bruso

(c) Colleen Bruso

Of the three species, this is the one you’re most likely to see. A highly adaptable animal, it’s found across much of North America, Europe, and Asia, and survives well in built-up environments.

To identify a red fox, look for these characteristics:

  • Rusty red back and sides (though the coloration is variable and young pups are tan-colored)
  • Black ears
  • Black lower legs, as if it’s wearing dark stockings
  • A long tail, often nearly as long as the body, with a white tip

Gray fox (Urocyon cinereoargenteus)

137LincolnClark3829

(c) Lincoln Clark

This amazing animal isn’t just a grey-colored red fox—it belongs to a different genus, or group in the animal family tree, and has some unusual traits. Like a cat, its nails are retractable, and it can climb trees and jump from branch to branch. It’s more rarely encountered because it doesn’t wander as much and tends to stick to its forest territory.

Here’s how to tell you’re looking at a gray fox:

  • Grizzly grey back (though reddish around the head and legs)
  • No black “stockings” as in the red fox
  • A black stripe that runs the length of the tail, and a black tail tip

Coyote (Canis latrans)

(c) Kristen Donovan

Adult coyotes are more than double the size of gray foxes, and coyotes in the eastern US tend to be bigger than those in the west. Evidence suggests that the coyote interbred with the eastern Canadian wolf as it spread into the northeast in the past century. The resulting animal is larger than the western coyote, and has some wolf-like characteristics, including smaller ears and longer legs.

However, it’s still much smaller than the wolf, which was wiped out in Massachusetts by the early 19th century. The coyote is very adaptable and can be found in developed areas, but tends to be shy and elusive.

Here’s how to identify a coyote:

  • Color varies greatly but is usually gray to cinnamon gray
  • Heavy build
  • Long legs
  • A relatively short, dark-tipped tail that hangs down when it runs

Learn more about coyotes on our Nature and Wildlife pages, and share your wild canine sightings with us here and on our Facebook page.