Zebra finches: Is female mate choice repeatable across males with nearly identical songs?

Is female mate choice repeatable across males with nearly identical songs? Daiping Wang et al. Animal Behaviour, October 11 2021. https://doi.org/10.1016/j.anbehav.2021.09.001

Highlights

• Individual-specific mate preferences are common but poorly understood.

• Mate preferences differ strongly between individual female zebra finches.

• Individual males differ strikingly in their songs.

• Females respond differently to males with exceptionally similar songs.

• Song traits are hence not the target of individual-specific preferences.

Abstract: Individual-specific mate preferences are thought to be widespread, but they are still poorly understood in terms of mechanisms and function. Earlier work on a songbird (the zebra finch, Taeniopygia guttata) showed predominantly individual-specific mate preferences and signs of behavioural incompatibility with certain partners. However, the phenotypic target of preference or aversion remains unclear. A previous study suggested that female preferences may be related to variation in male song. Male zebra finches have individually distinct songs and together with individual-specific female song preferences they could function according to a ‘key–lock principle’. Here we report on a preregistered study in which we tested the hypothesis that individual females respond to males with highly similar songs in a similar way. We selected 18 duos of males with nearly identical songs and released them with females in communal breeding aviaries. We scored female preference as the female's responsiveness to male courtship and confirmed that females indeed had strong individual-specific mate preferences. However, female responsiveness scores were not positively correlated across males closely matched for their song, thereby rejecting the idea of a song-based ‘key–lock principle’ as an explanation for the observed individual-specific preferences. We suggest researchers should focus on details of the interactions between potential partners to elucidate the cause of behavioural incompatibility.

Keywords: behavioural compatibilitybirdsongindividualitymate choicemate preferencesmonogamypreregistration