The two volumes of John Wiens' Ecology of Bird Communities have applications and importance to the whole field of ecology. The books contain a detailed synthesis of our current understanding of the patterns of organisation of bird communities and of the factors that may determine them, drawing from studies from all over the world. By emphasizing how proper logic and methods have or have not been followed and how different viewpoints have developed historically and have led to controversy, the scope of these books are extended far beyond the study of birds. Processes and Variations discusses the way in which bird community patterns have been interpreted. This second volume examines how the complexity and variability of natural environments may influence efforts to discern and understand the nature of these communities. Graduate students and professionals in avian biology and ecology will find these volumes a valuable stimulus and guide to future field studies and theory development.