Data from: A test for repertoire matching in eastern song sparrows

Repertoire matching occurs when one songbird replies to another with a
song type that the two birds share. Repertoire matching has previously
been demonstrated to occur at well above chance levels in a western
population of song sparrows, where it is hypothesized to serve as a low
level threat in a hierarchy of aggressive signals. Here we test for
repertoire matching in an eastern population of song sparrows. Previous
work indicates that this eastern population differs from the western one
in having lower levels of song sharing between neighboring males and in
showing no association between song sharing and territory tenure. Here we
confirm that males in this eastern population on average share few whole
songs with their neighbors. The eastern males are familiar with their
neighbors’ repertoires, as evidenced by a stronger singing response to
stranger song than to neighbor song. Males in the eastern population did
not repertoire match: when played an unshared song type from a specific
neighbor, they did not reply with a song type shared with that neighbor
more often than expected by chance or more often than in response to
playback of a control song (an unshared stranger song). The results thus
demonstrate a qualitative difference in vocal signaling strategies between
two populations of the same species.