An important empirical test of the theoretical predictions of sexual selection theory this book presents a long-term field study of the monagamous barn swallow. By using information on behaviour ecology morphology genetics and evolution the book reviews this theory and its two components: male-male competition and female choice.The selective advantages of a long tail are investigated for this common bird demonstrating such effects as mating behaviour copulation behaviour migration strategies and host-parasite interactions.A rich informative text which clearly elucidates the mechanisms and consequences of sexual selection.