Similarity of playback songs to self song as a determinant of response strength in song sparrows ( Melospiza melodia)

Abstract

Male song sparrows ( Melospiza melodia) were presented with a series of four playback songs of decreasing similarity to their own song. Strength of territorial response was inversely correlated with similarity of the stimulus song to the subjects' own songs. The males discriminated between the songs of strangers within their own population, based on whether the stranger's song was of the same ‘cadence type’ as a song in the subject male's repertoire. Habituation to self song is not considered an adequate explanation for the observed results. Instead, an active recognition of similarity to self song is postulated, the function of which is not clear. To the degree that self song has a unique salience to the males, song sparrows can be said to have an auditory concept of ‘self’.