In a playfully far-fetched story within a story, an ""amateur zoologist"" named Dr. Frederick Fluke explains to Lucas and his four year-old sister Sara, over sundaes at the restaurant terrace, why the Central Park seals are temporarily inactive. It turns out that they are hiding a fugitive Great Auk, whom Fluke has rescued from a truck bound for the Bronx Zoo, in order to protect its native Arctic regions from the invasion that would certainly follow identification of a bird long considered extinct. Most of Fluke's story is taken up with the banter and squabbling of the Auk's caged companions -- a bear, a lemming, etc. -- and how children take to all this verbal diversion will determine their response to the book. Though the badinage can be coy ("" 'Alas, poor Curlew,' sobbed the Ptarmigan. 'I knew him well. . .'"") or even snobbish (the truck driver shouts ""I ain't no mammal! I'm a human bean and a hundred per cent American!""), certain sophisticated children will enjoy the owl's predacious predilections (""I have a sweet tooth for Lemming short ribs and Auk pope's nose""), the rapid exchange of insults, and the general contempt for Man. Far more universally appealing are William Pene Du Bois' gently but wittily expressive pictures of the white arctic animals, properly outfitted children, and eccentric sneaker-clad narrator. Together with the fine production they ensure that the book will attract its share of readers.