A New Yorker writer with several children's books about wildlife to her credit describes adopting an unweaned ""chuck"" found near her Rhode Island home, raising him, and then returning him to the wild. Gracefully, succinctly, and without sentimentality, she characterizes Chuck as an engaging little chap with ""amazing energy and will""--and, meanwhile, unobtrusively tucks quite a lot of natural history into her accessible text; she even shapes the true facts into a satisfying drama, concluded lay a poignant second and final farewell at hibernating time. Wildlife artist Morrell's soft-pencil b&w illustrations are appealing and precise. A charming vignette.