Shortlisted for the BB/BTO Best Bird Book of the Year 2022. The first comprehensive coverage of a subject that has fascinated natural historians for centuries. Avian vagrancy is a phenomenon that has fascinated natural historians for centuries. From Victorian collectors willing to spend fortunes on a rare specimen, to today’s high-octane bird-chasing ‘twitchers’, the enigma of vagrancy has become a source of obsession for countless birders worldwide. Vagrancy in Birds explores both pattern and process in avian vagrancy, drawing on recent research to answer a suite of fundamental questions concerning the occurrence of rare birds. For each avian family, the book provides an in-depth analysis of recent and historical vagrancy patterns, representing the first comprehensive assessment of vagrancy at a global scale. The accounts are accompanied by hundreds of previously unpublished images featuring many of the most exceptional vagrants on record. The book synthesises for the first time