A twig falls from a tree and lands on my hat — I feel a gentle tap, much too light for an acorn. I take the hat off and watch as the twig arches and inches forward: an inchworm, the larva of a geometer moth.
It crosses the machine-stitched message on the front of the cap — another chance — and the lower wing of the ivory-billed woodpecker. I bought the cap last November on a visit to Brinkley, Arkansas (see here and here) and have worn it regularly ever since. The colors have faded quite a bit. The dot of yellow thread in the woodpecker’s eye has become virtually invisible, and its black-and-white suit looks ready for a trip to the cleaners. Unfortunately, it’s hard to wash a ball cap without shrinking it or warping the brim.
I am among those who continue to believe in the ivorybill’s rediscovery, because I believe in Occam’s Razor, that rule of logic which asserts that the simplest explanation that accounts for every case is most likely to be correct. The many small pieces of evidence and testimony, though hardly unassailable by themselves, do add up, inch by inch. Skepticism and cynicism risk nothing, but they also offer few rewards beyond the sense of membership in an elite club of fellow Brights.
Geometer means “earth-measurer.” The inchworm — also known as a spanworm or looper — takes the earth’s measure with its body, one prostration at a time. This isn’t a progress, but a pilgrimage, with no goal other than to be a caterpillar: it very likely has no notion that any transformation lies ahead. It reaches the far side of my hat and stretches out into space. I flick it onto the ground and watch to make sure that its course takes it away from the tractor tires. The next morning, there’s news of another ivorybill discovery, this time in the Florida panhandle.
Our observations, acoustic encounters, audio recordings, measurements of cavities, and analysis of feeding sign provide evidence that Ivory-billed Woodpeckers may live along the Choctawhatchee River in the Florida panhandle. In a 1-year period from 21 May 2005 to 19 May 2006, members of our search team saw birds that we identified as Ivory-billed Woodpeckers 14 times. We heard sounds matching Ivory-billed Woodpecker kent calls and double knocks, and our listening stations recorded numerous putative kent calls and double knocks, including both sounds at the same recorder on the same day. At the location of our sightings and sound detections, we documented trees with very large cavities with dimensions exceeding the published range for Pileated Woodpecker cavities and exceeding sizes of cavities measured in a nearby area where Ivory-billed Woodpeckers are known not to occur. Also at this same location, and sometimes on the very trees with large cavities, we observed bark scaling unlike that seen in other southern bottomland forests. Any one of our lines of evidence could be dismissed as coincidental or a mistake, but together, these observations, collected by experienced ornithologists, suggest that Ivory-billed Woodpeckers may be present in the Florida panhandle. The persistence of Ivory-billed Woodpeckers will be established definitively only by a clear photograph or video image, a fresh feather, or perhaps genetic analysis of material from a nest or roost cavity, but the evidence presented here warrants an expanded search and protection of this bottomland forest habitat.
It seems we may still have another chance to get it right.