The first book to approach the morphological, physiological and behavioral development of birds from an ecological and evolutionary perspective. Following the natural development from embyro to mature bird, it covers traditional topics such as breeding biology, egg and clutch size, and breeding success, but integrates these subjects with recent information on energetics, thermoregulation, and mortality rates. This approach allows new insights into previously unrelated phenomena such as mate recognition, navigational ability, song, sibling aggression and fratricide.