Behaviour 2019
Structurally Complex song of Female House Finches
Ar Kornreich, Mason Youngblood, Paul C. Mundinger, David C. Lahti. City University of New York, New York, New York, United States

In temperate avian species, female song is typically less common and structurally complex than male song. Although rare anecdotal accounts suggest that female house finch song is less complex, it has never been quantitatively compared with male song. We quantitatively analyzed songs of two house finch populations living in southern New York to investigate the degree of sexual dimorphism in complexity, as measured by concavity, frequency excursion, and length of song. We found that, although females sing at a significantly higher average frequency and lower bandwidth, there is no significant sex difference in the structural complexity of song. Future research should investigate whether female house finch song has an unrecognized function, or whether the retention of complexity is a byproduct of selection for a correlated trait.