Migration has always fascinated birdwatchers but the extraordinary journeys undertaken by birds are even more amazing now that know so much more about them through ringing and radio-tracking. This book is an introduction to the subject designed to appeal to those with only a limited knowledge through to moderately experienced birdwatchers. Initial chapters explain what migration is and why birds migrate, together with an overview of ringing activities and radio tracking. Seven chapters then divide up around 250 species into the main UK habitat groupings to discuss their migratory habits. This is an interesting approach, avoiding the tried and tested family-by-family route. Each species is covered in around 150-200 words, although for many species there is rather too much information about plumage and other characteristics that have nothing to do with migratory movements. About 100 maps are used to show the main migration routes taken and many colour photographs accompany the text. Another chapter deals with vagrancy. Time to Fly is effectively a distillation of the key information from "The Migration Atlas" published two years ago. At a fifth of the size it deserves to reach a wide audience and will enhance their appreciation of a complex subject.