Sunday, December 8, 2019

More Bears than Birds

On this mild, cloudy afternoon in Columbia, Missouri, my wife and I took a walk around Perry Phillips Lake, south of town.  Despite the pleasant weather, I observed only a handful of bird species, all common, permanent residents.  Indeed, I saw more woolly bear caterpillars than birds.

These fuzzy, black and orange banded caterpillars, known to even casual observers of nature, are the larvae of Isabella tiger moths.  Emerging from eggs in summer, they spend the remaining mild-weather weeks feasting on a variety of plants; once winter threatens their survival, they search for a sheltered site beneath logs, rocks or leaf litter to hibernate.  Come spring, these caterpillars spin a cocoon and pupate, emerging as adult moths two weeks later.

Rumored to predict the severity of winter by their fuzziness or by the thickness of their central band, woolly bears are certainly among the last insects active in the fall and are sometimes observed crossing snow banks.  On this December afternoon, they were the dominant species of wildlife along the 1.4 mile trail loop.