Beginning birdwatchers face many frustrations: birds, it seems, are constantly in motion, taking flight before the fledgling birder can turn to a photograph or drawing that might help pinpoint its identification. The experienced birdwatcher, Edward Cronin writes in this friendly manual, is by contrast able to identify a dozen species in a few seconds, which compounds the beginner's lack of self-confidence. Never fear, Cronin reassures us: The "magician's trick of rapidly identifying species is, in truth, based on a logical procedure that anyone can master." One great secret, he goes on to say, is that most often a bird is.