The actual existence of screech owls, horned owls, barn owls etc., has fired the imagination of poet John Hollander and artist Tomi Ungerer who abandon the mundane world of real hooters for a forest of their own species. Perched upon these branches we find Alfred the scowl owl, Roger the vowel owl, Duff the growl owl, Toby the jowl owl, even Mustapha the howl owl. The special talents of each are described in terse verse while their physical characteristics come across perfectly in large staring pictures, whose dark colors surprisingly contribute to the general gaiety. One looks for more lilting rhythms and funnier images because the original conception and the pictures are so clever. Mr. Hollander's poems are adequate, but not inspired.