I’m visiting the University of Richmond where, just like Sewanee, spring is in full force and many weeks early. In addition to great people and beautiful buildings, the campus is populated by millions of inchworm caterpillars. Just walking between buildings results in the acquisition of half a dozen hitch-hikers, each one hanging by a silk thread from above, presumably drfiting down to new feeding areas or places to pupate. These caterpillars belong to the Geometrid moths, a family of brown moths named for the looping walking habit of the caterpillars — they appear to “measure, metron, the Earth,Geo,” as they walk along.
These seemingly insignificant creatures are one of the hinges on which our changing world swings.
The caterpillars come out when the oaks and other trees first unfurl their leaves. The young leaves have not yet had time to accumulate toxins to deter the inchworms, so the little caterpillars feast quickly, then their numbers dwindle.
Migrant birds time their arrival to catch the burst of caterpillars (food!). But, lately, the caterpillars are emerging so early that by the time the migrant birds arrive, the party is over. In Europe, this mistiming is so severe that it has caused significant population declines in some birds.
How or whether these dissonant changes in tempo will resolve is unclear.