Recognition of Neighbors' Song in a Species with Large and Complex Song Repertoires: The Thrush Nightingale

Abstract

To investigate aspects of neighbor recognition in a migratory bird with large and complex song repertoires we conducted playback experiments in the field with male territorial Thrush Nightingales Luscinia luscinia as subjects. Males sing with immediate variety and neighbors can share a considerable part of their repertoire of song components and song types. Subjects responded significantly more to their neighbors' song broadcast from the unshared (opposite) territorial boundary than to playback of the same song broadcast from the shared territorial boundary. Thus, this study did not detect constraints on neighbor recognition imposed for instance by large and complex song repertoires, high singing versatility, or sharing of song patterns. Because Thrush Nightingales sing shared patterns in different ways, either by constructing different song types out of the shared pool of elements or by singing shared song types in different sequential order, they could attend to song components and their syntactical arrangement, full songs, or their sequential delivery for neighbor recognition. Which mechanism they use might depend on the similarity of the song and singing style of a singer compared to other familiar conspecifics.