Species‐specific coding strategies in bird song

Perceptual specializations exhibited by two species of North American blackbirds in the perception of their own species‐specific songs are described. Redwing blackbirds (Agelaius phoeniceus) and brown‐headed cowbirds (Molothrus ater) were trained to identify, using a go‐right, go‐left procedure, categories of complex song themes from their own, and from the other (control) species' repertoire. Themes were then broken up and birds were required to identify the constituent elements (“introductory notes” versus “trills” or “whistles”) of the themes. Results revealed that birds tend to process their own species‐specific songs as total patterns, possibly making use of some sort of “template” matching. In contrast, songs of the control species seem to be processed by a serial examination of stimulus dimensions. Human perception of these stimuli is also discussed. [Supported by Grant No. NS12112 from NIH.]