Why are humming birds found only in the Americas? Why are the Barn Owl and Osprey found on virtually every continent? What accounts for the high level of endemism at both family and special levels in Australia? Why have some birds prospered and proliferated, while others enjoy only the tiniest population? What led to the extinction of such birds as the Tuamotu kingfisher, the Dodo or the Laughing Owl? Why did the Bowerbirds evolve such elaborate behaviour...