Walking the dogs one unseasonably warm day last week I was stopped in my tracks by something I'd never notice before: the sidewalk was evenly speckled by wood fibers. I first looked around for signs of chainsaw work. Nothing. Then, seeing that the fibers were soft and rotten, I looked to see if a rotten limb had fallen. Nope.
I walked on, filing it under minor mysteries, until I saw it again. This time, looking up, I could see the remains of a dead limb positively honeycombed by large, round holes. That gave me my answer: woodpeckers had been at work--or perhaps just one--going from tree to tree in search of juicy insects hiding in the rotten wood, leaving the results of its jackhammering on the sidewalk beneath. The work was probably done by the downy woodpecker, since that's the only woodpecker I've seen around (not counting the ground-feeding northern flicker).