This book should be of value to anyone interested in bird evolution and taxonomy, biogeography, distributional history, dispersal and migration patterns. It provides an up-to-date synthesis of current knowledge on species formation, and the factors influencing current distribution patterns. It draws heavily on new information on Earth history, including past glacial and other climatic changes, on new developments in molecular biology and palaeontology, and on recent studies of bird distribution and migration patterns, to produce a coherent account of the factors that have influenced bird speci