Owl, 14, is charmingly offbeat; she hangs out at night in a tree near the home of her one love--science teacher Mr. Lindstrom. What makes her nocturnal vigils relatively easy is that she's a ``wereowl'' whose nightly transformation ruffles her feathers no more than does her diet of rodents. Wereowls run in the family, so Owl is comfortable with her identity, though the efforts demanded by her one-sided love are wearing her a bit ragged. When she observes a boy lurking near Mr. Lindstrom's home, the stage is set for shedding the schoolgirl crush for a more transcendent romance. Owl's perspective is no birdbrained view; readers are soon solidly immersed in her wild, wise, and witty ways. Lofty phrasing, wry self-awareness, and passionate musings frame and fill a delightful first-person narration. Owl's quaint parents play several scenes for humor and have foibles enough to complete Owl's typical teenage alienation. The tidying up at the end is a little overneat and abbreviated; otherwise, an unusually strong and original first novel. (Fiction. 10+) -- Copyright ©1993, Kirkus Associates, LP.