The Flammulated Attila sings two acoustically distinct song types. Dawn songs have up to six elements, four of which occurred in the main phrase and two others in the terminal phrase. Birds sequenced these elements inflexible but predictable ways. Attilas varied the number of repetitions of dawn song elements before going on to the next element or ending the song. They combined elements in different ways by using two different starting elements and three ways of ending songs. Ignoring variable repetitions of song elements, 22 different patterns were observed at least once. Most birds had four or more patterns present in the recorded sample of their singing. Individual birds that were known to have elements in their repertoire often omitted some of these elements from songs.
Day songs seemed to be less flexible than dawn songs, but birds often failed to give the terminal phrase, sang the terminal phrase without first singing the main phrase, or repeated the terminal phrase. Day songs also varied in the number of repetitions of the most common note of the main phrase. Dawn and day songs of a tyrant flycatcher, the Flammulated Attila (Attila flammulatus), were recorded in Costa Rica. Flexible syntax was noted in both dawn and day songs. Attila’s not only varied the number of repetitions of their song elements but also combined elements in various ways. This appears to be the first reported case of combinatorial song syntax in a suboscine species.
