First Documentation of Combinatorial Song Syntax in a Suboscine Passerine Species

Birds with songs having two or more acoustically distinct elements can arrange them either rigidly (i.e., in the same sequence) or flexibly. Flexible song syntax can be achieved either by varying the number of repetitions of elements or by combining elements in different ways. Combinatorial syntax has been documented only in the songs of oscine passerines and in one nonpasserine, but not in the suboscine passerines. 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 song. Attilas 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.