The Flexible Phenotype attempts a true synthesis of animal physiology, behaviour, and ecology by developing an empirical argument that describes the intimate connections between animal phenotype and environment. It starts with a synthesis of the principles guiding current research inecophysiology, behaviour, and ecology, illustrating each aspect with the detailed results of empirical work on as wide a range of organisms as possible.The integrated story of the flexible phenotype is weaved throughout the book on the basis of the authors' long-term research programme on migrant shorebirds and their invertebrate prey. These birds travel vast distances from one environment to another, and the changing nature of their bodiesreflects the varied selection pressures experienced in these very different locations. In essence, the authors argue for the existence of direct, measurable, links between phenotype and ecology. Their book outlines a more encompassing approach to evolutionary ecology, based on first principles inphysiology, behaviour, and ecology. It aspires to encourage a further integration of ecology and physiology, as well as fostering a collaborative research agenda between ecologists and physiologists.