Use of the extensive vocal repertoires in the Grass Wren Cistothorus platensis during agonistic interactions

GARCIA N C; LLAMBIAS PAULO E

Congreso; Ornithological Congress of the Americas; 2023

Association of Filed Ornithologists

The Grass Wren, Cistothorus platensis (Passeriformes: Troglodytidae), is a species with extensive vocal repertoires, ranging from 100 to 300 songs per individual in the populations studied to date. A large proportion of these songs are shared among males of the same population, indicating that the repertoires are developed through imitation of neighboring males rather than improvisation, as occurs in other species of the genus with nomadic or migratory populations. It has been proposed that imitation would be advantageous in sedentary populations, where potential rivals are known because it would allow for song-matching (responding to the rival with the same song) as an aggressive signal. However, this behavior has not been extensively studied in Grass Wren males. Here, we analyze natural interactions recorded opportunistically and playback experiments in a sedentary population in Mendoza, Argentina. Our preliminary results indicate that males engage in song-matching when they share songs with their neighbors, but not in all interactions. We also found that males do not engage in song-matching when we simulate the intrusion of a male with non-shared songs. These results provide evidence for the hypothesis that the development of repertoires through imitation is advantageous because it allows for the use of song-matching, but a more detailed study of the context of such interactions is needed to understand under what circumstances this behavior is employed. Our results also suggest that adult males cannot imitate songs they are unfamiliar with in order to engage in song-matching.