Describes the prominent themes in the ecology, natural history, and evolution of bees, and includes discussions on pollinating behavior, natural enemies, reproduction, social behavior, and maintenance of the diversity of tropical communities. This book is the first to draw together these themes, and covers topics as varied as the evolution of obligate sociality and the reproductive diversity of tropical flowering plants. There are many new examples from the author's research on pollination ecology, mimicry, mutualism, coevolution, and competition.