We all know Cuckoos as the harbingers of spring - whose haunting calls proclaim the birds own name across fields and reedbeds. A bird much more often heard than actually seen, and often mistaken for a hawk or falcon when briefly glimpsed in flight. Cuckoos are also well known, perhaps even infamous, for their habit of laying their own eggs into the nests of much smaller species, such as reed warblers, who are then doomed to raise the enormous cuckoo chick rather than their own young, and whose eggs are ruthlessly thrown from the nest by the cuckoo hatchling. But how does this complex behaviour act out in nature, and how did it evolve? What are the cuckoo's special tricks and what counter-measures have the host birds developed to resist the depredations of cuckoos? In this book the authors delve into the stories behind what we see, and into the complex and ever evolving evolutionary arms race by which the nest parasite and its hosts constantly try to leapfrog each other into prime position. The natural history of the cuckoo-host struggle is illuminated with detailed explanations of the results of behavioural and ecological research to provide a comprehensive, but highly readable, account in which an insight into one puzzle constantly reveals a new question begging an answer. The whole story is brought vividly to life through the astonishing photographs of Oldo Mikulica, who has watched cuckoos and their various hosts from hides for almost four decades. The result is a unique and beautiful book which both informs and delights.