The book on the example of a compact group of birds of the Swan subtribe discusses methodological approaches in comparative ethology, as well as the principles of analytical description of signaling behavior suitable for subsequent taxonomic constructions. The basic information on ecology and social behavior of all species of swans of the world fauna is given. The history of their discovery by ornithologists and transformations in the ideas of taxonomists about the structure of the taxon is described. The book is written in a good, easy-to-read (not even specialist) language. In addition to behavior (and in organic conjunction with it), almost all the main aspects of the biology of swans and their relatives are covered, including ecology, morphology, demography, biogeography, reproductive cycle features, ontogenesis, and many others.