The Role of Song in Individual Recognition in the Indigo Bunting

Emlen, S.T. 1971. Zeitschrift fur Tierpsychologie, 28:241-246.

Territorial male Indigo Buntings respond aggressively to playback of conspecific songs. However, recorded songs of familiar, neighboring individuals elicit a much weaker response than do songs of unfamiliar buntings residing some distance away. Such individual recognition by voice is considered adaptive in minimizing the energy expended in needless territorial encounters.