EVEN ON THE windiest days, and in the most unpromising places, you’re likely to meet a wren. Harried by bitter gale-force gusts, I was being blown along a low-cut hedgerow when I caught sight of the bird. Just a brown blur passing through the bottom of the hedge, the wren disappeared into the thick clumps of last year’s grass, searching for insects. It reappeared then slipped, mouse-like, into a tiny opening in a pile of stones. This habit of delving into the nooks and crannies gave the wren its Latin name, Troglodytes troglodytes, which literally means cave dweller. Darting back up into the hedge, the wren burst into song. Tiny it may be, but its song is amazingly loud. And subtle. Even experienced sound technicians find it hard to record a wren’s call because of the co