The present study was undertaken to test and evaluate the various taxonomic arrangements of the family, to discover some of the trends of behavioral evolution, and to provide a basis for future workers to use in naming, describing, and evaluating the behavioral patterns observed in waterfowl. The major sexual behavior patterns of the species of Anatidae are reviewed and summarized, for the purpose of clarifying evolutionary relationships in the family, tracing the evolution of behavior patterns through various taxa, and evaluating the importance of certain behavior patterns as potential isolating mechanisms. Species treated include: Magpie Goose, Fulvous and Cuban Whistling Ducks, Whistling Ducks, Mute Swan, Black Swan, Black-necked Swan...