Males use time whereas females prefer harmony: individual call recognition in the dimorphic blue-footed booby

► We analysed calls of blue-footed boobies and did a playback experiment. ► An individual signature was present and acoustic variables differed between sexes. ► Individual identity was encoded by temporal (male) and spectral (female) parameters. ► Male and female signals were equally effective for mate recognition. ► The decoding process may differ between the sexes.