Developmental stressors that impair song learning in males do not appear to affect female preferences for song complexity in the zebra finch

A number of recent studies have provided evidence that the environmental factors experienced during development contribute to variation between females in the direction and strength of their mating preferences. The developmental stress hypothesis suggests that the complex male songs of many songbirds and female preferences for those complex songs have evolved because song quality reflects how well an individual was able to cope with suboptimal developmental conditions. In this study, we tested whether female preferences for song complexity are affected by developmental stress. Female zebra finches, Taeniopygia guttata, were raised under conditions of nutritional stress or control conditions. In adulthood, their song preferences were tested in an operant setup where females could trigger playback of song recordings by landing on different perches. The subjects could choose between pairs of songs that were digitally manipulated to ensure that they varied only in the number of syllables in the song. Across all subjects, there was a significant preference for the more complex song of the song pair, but there was no difference between the treatment groups in the direction or strength of their preference. These results suggest that adverse developmental conditions do not impair females' ability or motivation to discriminate between songs on the basis of complexity and thus to obtain information about potential mates' developmental history.