John James Audubon's double elephant folio edition of The Birds of America (4 vols., 1827-38), a massive work of natural history that offers the reader an innovative interplay between image and text, still stands as one of the most remarkable artistic and scientific achievements in the history, of the hook. For Audubon, though, producing this 'Great Work' proved to be as much about entrepreneurship as ornithology. The changes in the popular perception of Audubon's birds from his time to our own is the background for looking at the connection between the cultural and commercial significance of this big book about birds, which represents both an investigation of nature and an investment in art. The various ways people have valued Audubon's work leads to the question of whether The Bird of America is--or should be--a hook at all.