Flight Songs of Swamp Sparrows: Alternative Phonology of an Alternative Song Category

Abstract

In addition to their simple trilled territorial song, normally sung while perched, male Swamp Sparrows (Melospiza georgiana) more rarely also sing a flight song with complex phonology and syntax. The typical trilled songs of Swamp Sparrows all can be broken down into only six simple constituent note types. Because these same note types, and no others, are found throughout the Swamp Sparrow's range, they are thought to represent a "species-universal phonology." Acoustic analysis of flight song notes from one population reveals no overlap at all with the phonology of trilled songs. One flight song note type ("B") appears similar to a trilled song note type ("VI"), but detailed analyses reveal these note types to be distinct. Thus, Swamp Sparrows appear to use independent phonologies in the production of two different types of song. These two phonologies may entail different mechanisms for processes of song acquisition and control.