Whether soaring or perched, diurnal birds of prey often present challenging identification problems for the bird enthusiast. Variable plumage, colour morphs, and unique individual characteristics are just some of the factors bird watchers must consider when identifying the different species. In this authoritative reference, two of the world's top experts on raptors provide an essential guide to the variations in the species, allowing for easier recognition of key identification points. All the distinguishing marks described have been exhaustively tested in a wide range of field conditions by the authors as well as the colleagues and students who have learned from them. Key Features * The only complete photographic guide to North American diurnal birds of prey * Includes all species, common and rare * Written by well-known experts