Male song structure predicts reproductive success in a wild zebra finch population

► Zebra finches are a model species for behaviour but are rarely studied in the wild. ► We investigated male song and reproductive success in a wild zebra finch population. ► Principal components of father's song predicted hatching and fledging success. ► Analysis suggests this reflects indirect benefits provided by the male, not indirect effects. ► Wild males sang longer songs with a higher peak frequency than domesticated males.