This winsomely imagined account of an episode when Audubon was 18 years old joins the flocks of commemorative works. Sent to the US to learn business, the young man happened upon a mated pair of pewee flycatchers; these he made an object of exclusive study, sketching and painting of course, but also banding the fledglings with silver thread to discover whether they would return after their winter migration—the first such experiment done in North America. Davies’s narration, though bolstered by an author’s note and bibliography, blends fiction into fact, recreating dialogue and Audubon’s own internal thoughts with no specific reference to written sources. This significant weakness is balanced by the tight, appealing focus on a lonely, bird-obsessed young man whose perfectionism led him to burn his artwork every year and who burned to demystify the migratory habits of small birds. Sweet’s illustrations soar, incorporating mixed-media collage into her line-and-watercolor paintings in a gloriously eclectic mélange that evokes both the time and Audubon’s scientific enthusiasms. A solid offering that, were it more completely sourced, would be nothing short of tremendous. (Picture book/nonfiction. 6-9)