Male and female Rufous-and-white Wrens do not match song types with same-sex rivals during simulated territorial intrusionsMoser-Purdy, Christopher; Kahn, Zachary; Graham, Brendan; Menill, Dan
22 May 2019
In birds with song repertoires, song-type matching occurs when an individual responds to another individual’s song by producing the same song type. Song-type matching has been described in multiple bird species and a growing body of evidence suggests that song-type matching may serve as a conventional signal of aggression, particularly in male birds in the temperate zone. Few studies have investigated song-type matching in tropical birds or female birds, in spite of the fact that avian biodiversity is highest in the tropics, that female song is widespread in the tropics, and that female song is the ancestral state among songbirds. In this study of rufous-and-white wrens (Thryophilus rufalbus), a resident neotropical songbird where both sexes sing, we presented territorial males and females with playback that simulated a territorial rival producing shared and unshared songs. In response, both males and females sang matched song types at levels statistically equal to levels expected by chance. Furthermore, males and females exhibited similar levels of aggression and similar vocal behaviours in response to playback of both shared and unshared songs. These results indicate that rufous-and-white wrens do not use song-type matching in territorial conflicts as a conventional signal of aggression. We discuss alternative hypotheses for the function of song-type sharing in tropical birds. In particular, we point out that shared songs may play an important role in intra-pair communication, especially for birds where males and females combine their songs in vocal duets, and this may supersede the function of song-type matching in some tropical birds.