A method to measure the development of song preferences in female cowbirds, Molothrus ater

Male song development has been studied in detail across a range of different songbird species. Very little, however, is known about the development of preferences for songs in females. Here we describe a method to study female preferences outside the breeding season by documenting female responses to playbacks of songs of different developmental stages and of varying quality. We compared ‘wingstroke’ responses of juvenile and adult females in four groups across autumn, winter and spring. We found that adult, but not juvenile, females showed preferences for variable song that was developmentally advanced. We assessed female preferences for the songs in the breeding season by playing back songs in sound-attenuation chambers and recording the number of copulation solicitation displays females gave to each song. We detected a strong relationship between wingstroke patterns in spring and song preferences, but we did not detect this relationship in the autumn or winter. Female preferences, like male songs, appear to show seasonal and developmental plasticity.