Despite the depiction of nature 'red in tooth and claw' that is still all too common, cooperation is actually widespread in the animal kingdom. Various types of cooperative behaviors have been documented in everything from insects to primates, and in every imaginable ecological scenario. Yet why animals cooperate is still a hotly contested question in the literature on evolution and animal social behavior. In Cooperation Among Animals: An Evolutionary Perspective, Dugatkin examines the history surrounding the study of cooperation, and proceed to examine conceptual, theoretical and empirical work on this fascinating subject. He outlines four different categories of cooperation reciprocal altruism, kinship, group selected cooperation and byproduct mutualism and attempts to tie these categories together in a single framework called the Cooperator's Dilemma. Hundreds of studies on cooperation in insects, fish, birds and mammals are then reviewed. Cooperation in this wide array of taxa includes, but is not limited to cooperative hunting, cooperative antipredator behavior, cooperative foraging, cooperative sexual coalitions, cooperative grooming, helper's at the nest, territoriality, 'policing' behavior and group thermoregulation. Each example outlined is tied back to the theoretical framework developed early on, whenever the data allows this. Future experiments designed to further elucidate on a particular type of cooperation are provided throughout the book.