Vocal Virtuosity in the Brown Thrasher

Abstract

Ethograms, or catalogues of behavioral acts, in a variety of animal species have typically revealed a relatively limited and finite number of behaviors (e.g. Kaufman and Rosenblum 1966, Wilson and Fagen 1974). This is also true for vocal behaviors in songbirds: some species may have only a single song (Marler and Tamura 1964), several wren species may sing approximately 100 songs (Verner 1975), and 'type-token' analyses for Mockingbirds (Mimus polyglottos) have yielded estimates of 66-244 song types for four males (Wildenthal 1965). Our recent studies reveal a vocal behavior in the Brown Thrasher (Toxostoma rufum) where song types of an individual number in the thousands and may even be improvised during display.