The relationship between syllable repertoire similarity and pairing success in a passerine bird species with complex song

► We investigated patterns of syllable composition in the collared flycatcher. ► We found a low degree of syllable repertoire overlap between males. ► Males that composed their repertoires from the same syllables realize similar mating success. ► There was a positive relationship between the distance between males and their repertoire overlap. ► Individual-specific song organization is important for listeners.