Vagrancy in Birds.

This article reviews *Vagrancy in Birds* by Alexander Lees and James Gilroy, a comprehensive examination of avian vagrancy, defined as birds occurring outside their normal range. The book explores the ecological, evolutionary, and conservation significance of vagrancy, addressing its causes such as reverse migration and population growth, and discusses challenges in defining vagrants. It provides detailed accounts of vagrancy across all bird families and considers the phenomenon in the context of global environmental change, emphasizing the importance of allowing natural vagrancy to facilitate species adaptation. The work is presented as a valuable resource for both researchers and birdwatchers interested in the ecological complexities of bird movement.