Deals with all aspects of this absorbing subject, including the problems of navigation and vagrancy, the timing and physiological control of migration, the factors that limit their populations and more. This book places emphasis on ecological aspects, which have recieved only scant attention in previous publications, providing the most thorough and in depth appraisal of current information available. Tables, maps, diagrams. Also includes a CD entitles 'Listening Landscapes: Sound Excursions to Nature in Azerbaijan'. Running time 74mins.