THE BTO/BRITISH BIRDS BOOK OF THE YEAR 2020A brand-new, completely revised second edition of Jenni and Winkler''s classic guide, updated and improved for the next generation of ringers and professional ornithologists.The moult strategies of birds exert an important influence on their behaviour and energetics, and also provide the basis of valuable tools for study. A proper understanding of how feathers are replaced and the precise differences in the appearance of the various feather generations can allow ringers, scientists and keen birdwatchers to age individual birds, and to distinguish between first-year and adult birds. Understanding the moult strategy of a species also provides insights into its general and migration ecology, and allows detailed studies of many aspects of its population dynamics. Lukas Jenni and Raffael Winkler have studied moult across a wide range of bird species for decades, and in this book bring their observations together to produce a va