Some birds have all the talent. Take the Mockingbird, for example. Mimic, composer, arranger, vocalist, clown, he still finds time to devote to his family. Like many another life-of-the-party, he gets his kicks by recording everything that happens and playing it back for all to hear, hi-fi and unedited. Thus his moonlight sonata is likely to be punctuated by variations on a theme from a power mower and Mrs. Catbird's conversation with Mr. Wren.