Woolly-bears on the move

 

A Woolly-bear (Pyrrharctia isabella) crosses a road. I saw many of these well-known caterpillars last Sunday. The temps were in the low to mid 40's F, but it was sunny, and the bears were on the move.

I was at the Wilds and vicinity in Muskingum County, Ohio, mostly looking for birds to photograph. But wandering larvae temporarily side-tracked my quest.

I did shoot some birds, including this Northern Mockingbird (Mimus polyglottos). He was nestled in a shrubby thicket, but when I stopped for a look, he popped out to look back. Mockingbirds are extremely in tune with their surroundings, from my experience, and pay close attention to detail. Far more than most songbirds, it seems. Perhaps this behavioral characteristic aids them in carefully listening to and learning the songs and sounds that they mimic so well.

Anyway, after about ten minutes of watching the mockingbird, hoping for an interesting flourish of the wings or something else of note, I was rewarded. The bird suddenly flew down to the road and seized a Woolly-bear that had wandered onto the pavement. Yes! But my hopes for photo documentation were soon dashed when it flew into the heart of the thicket to deal with its prey. I could not see how he dealt with the larval bear and all its stiff bristles, but I imagine it sliced it open with that stout bill and slurped out the innards. Baltimore Orioles (Icterus galbula) successfully feed on spiny Eastern Tent Caterpillars (Malacosoma americana) in this way.

This was the first time that I've seen a bird prey on Woolly-bears. Their dense coat of bristles probably is a pretty good bird deterrent, most of the time.

A Giant Leopard Moth caterpillar (Hypercompe scribonia) crosses a road not far from where the mockingbird grabbed the Woolly-bear. I saw many of these, too, although the Woolly-bears outnumbered them by a good margin. This caterpillar is somewhat larger and thicker than the Woolly-bear, all black, and when seen well the reddish-orange bands delineating its abdominal segments are diagnostic.

I suspect that Giant Leopard Moth cats are frequently mistaken for "dark" Woolly-bears". As you may know, there is a pervasive myth that the darker the Woolly-bear, the tougher the coming winter will be. However, any analysis of that myth would have to somehow take into account the problem with caterpillar misidentifications. There is yet another very common species of tiger moth, the Virginian Tiger Moth (Spilosoma virginica) whose caterpillars can be active into late fall. Its caterpillars are known as Yellow Bears (it isn't rare for adult moth species to go by a different common name than their caterpillars). Yellow Bears are variable in coloration but often resemble very pale Woolly-bears. Such larvae, when misidentified as they almost certainly commonly are, would be "light" Woolly-bears that forecast a mild winter.

This is what a Woolly-bear becomes, if not eaten by a mockingbird, Buick'ed while crossing a road, or bumped off in some other way. The Isabella Tiger Moth, a handsome insect. While legions of people know the caterpillar, probably very few would recognize the moth that it transforms into.

This is a Giant Leopard Moth, a truly stunning species and always a crowd-pleaser. A leopard in mint condition is an entomological work of art, with its array of black circles and iridescent blue markings. Press one gently with your fingers, and it may "reflex bleed": exude two amber droplets from the front of the abdomen, just above the head. It's a very cool effect, and the droplets presumably are toxic and assist in warding off predation by birds.