Animals perform many athletic tasks to an amazing degree of accomplishment: not only spectacular feats of running and jumping but also routine actions that ensure survival such as feeding, vocalization, diving, flying, and many more. The study of performance capacity (defined as the ability of an animal to conduct a key task) is of great interest to both ecologists and evolutionary biologists. At an ecological level, how well individuals perform often dictates opportunities for reproduction, occupation of preferred territories, or capturing prey. Therefore, variation in performance capacities can be a key determinant of variation in fitness within animal populations. At an evolutionary level, variation in function often follows closely from variation in form, and therefore enables animals to invade novel habitats, or to overtake other species. This novel book examines how and why animal athletes have evolved. It uses examples from across the animal kingdom and integrates them in the broader context of ecology and evolution, thereby identifying common themes that transcend taxonomic divisions. Animal Athletes is an accessible textbook of particular relevance to undergraduates, graduate students, researchers, and professionals in the fields of evolutionary biology, ecology, vertebrate morphology, and functional morphology, and will also appeal to the interested layperson.