Since the dawn of time people have wondered how birds could navigate from one end of the earth to the other, and back again, year after year, every year returning to the same area -- sometimes even to the nesting spot. This edition is a guide to the mysteries of bird migration. The illustrated introduction explains the background to bird migration - flight techniques, navigation, feeding and biology. New sections focus on the current environmental threat to migratory species and conservation initiatives worldwide. Informative text, the liberal use of illustrations and explanatory maps that trace the routes of more than 100 species reveal to the reader the fascinating facts about one of nature's greatest spectacles.