State of the world’s birds provides information on how birds can be used to focus action and as indicators to monitor change. Using the most up-to-date analyses presented in an attractive and accessible format, it outlines why birds and biodiversity are important, and examines what we know about the changing state of the world’s birds, why birds are declining and what can be done to improve their status. It synthesises current knowledge and provides a benchmark against which to assess future efforts to conserve birds and biodiversity.