This book looks at why and how birds moult, and the lasting effects that annual moults have on their appearance. By learning a few basic rules, we can use a bird's moult pattern to say how old the bird is and to understand more about its life-history.

Every bird moults, and every birder sees the effects of this – be it in the shift from winter to summer plumage, or in the often more subtle change from immature to adult. Many birders will want to know the age of the bird they’re watching, but a lot of us lack sufficient knowledge to determine age or are side-tracked by incorrect assumptions. But, by learning a few basic rules, anyone can add an extra dimension to their birding and their understanding of birds by getting to grips with this important aspect of avian life.

Rather than being a specific species-by-species guide, this book focuses on introducing the reader to general principles that can be used to understand the moult and age of virtually any bird. With these tools, we can use a bird’s moult pattern to say how old the bird is and to understand more about its life-history. Whether you are a beginner watching birds in the garden or a rarity-hunter trying to age a rare vagrant, A Practical Guide to Moult and Ageing will enrich your birding and enhance the data you gather.