The Migration of Birds

The work defines bird migration and assembles observations and theories about its causes and origins, balancing established facts with cautious speculation. Chapters examine migration routes and patterns such as broad-front and coastal movements, flight height and speed, orientation and route-finding, and the distances different species travel. Weather, winds, and the hazards of migration are analyzed alongside discussions of historical views and proposed mechanisms for transoceanic and storm-driven movements. The manual closes with summarizing suggestions, maps illustrating routes, and a bibliography for further study.