Birds live in polar ice deserts as well as in lush tropical forests, on distant islands and in our urban agglomerations. Their abundance of forms corresponds to an equally spectacular variety of ways of life and behaviour. Among blue tits, for example, late risers can be found as well as early risers or night owls. In Africa, bee-eaters let themselves carry around by bustards; the long-legged run-birds serve them as lookout and mobile starting-places for hunt-trips. And dunnocks live in the middle of our gardens in a relationship variety, which can keep up with each modern society. But as the urban environment grows, even the most intelligent birds face new challenges. How do they cope with the changes caused by humans? How do some species, some individuals succeed, and why do others fail? And how does man react to birds in his environment or how should he react?