Thrushes, warblers, vireos, and tanagers are probably the most familiar of the Neotropical migrants--birds that breed in the United States and Canada, then journey to spend the winter in the Caribbean, Mexico, or southward. But this extraordinary group actually comprises a large number of diverse species, including waterfowl, shorebirds, terns, hawks, flycatchers, and hummingbirds. In their compendious review of information on these birds, Richard...