Vagrancy in BirdsAn exploration of the causes and patterns of avian vagrancy Avian vagrancy the appearance of birds outside of their expected habitat is a phenomenon that has fascinated natural historians for centuries, from Victorian collectors willing to spend fortunes on a rare specimen to today's bird chasing "twitchers." Yet despite the obsessions of countless ornithologists, what do we actually know about the enigma of vagrancy? In Vagrancy in Birds, Alexander