Repertoires and Geographical Variation in Bird Song

Abstract

Publisher Summary This chapter deals with repertoires and geographical variation in bird song. Three methods have been used to investigate the function of a behavior pattern: (1) interspecific comparisons in which differences between species are related to ecological and life history variables; (2) intraspecific comparisons relating variations between individuals to variations in survival, reproductive success, or success in acquiring resources; and (3) direct experimental tests of the effect of a behavior. All three methods have been applied to the study of how selection favors repertoires. The chapter emphasizes micro-geographical variation, and examines the two factors that most significantly influence local spatial variation in bird song: (1) the extent and accuracy of imitation, and (2) the site of song imitation with respect to the site of breeding. It discusses the relationship between genetic separation of populations and song variations, and the influence of song repertoire size on the ability to establish or maintain sharp discontinuities in song traditions between neighboring populations. The usefulness and definition of the term “dialect” and the functional significance of vocal imitation and its influence on song dialects are also discussed.