Is he all he says he is? Intersexual eavesdropping in the domestic canary, Serinus canaria

Recent studies have pointed out that passerine females pay great attention to male territorial interactions and that they extract information on the quality of males from their territorial songs. We investigated whether female domestic canaries use information gained through eavesdropping when they choose mates. We evaluated the femalesʹ sexual preferences for taperecorded male songs previously heard during an ‘interaction-like’ situation during which the song of one male overlapped the song of the other. Females were tested during two consecutive experiments. In the first experiment, we measured the preference for male songs containing sexually attractive phrases; in the second, the attractive phrases were removed. When a sexually attractive phrase was included in the song, the females failed to show a significant preference but in the second experiment, the females preferred the songs of males that appeared to be able to overlap the songs of their opponents. In the first experiment, the information might have been contradictory: on the one hand, some males seemed to be of poorer quality than others, as they were losing the song contest, but, on the other hand, these same males were producing songs with a sexually attractive phrase, regarded as a signal of quality; the females might have been confused by this apparently inconsistent information. Overall, this study agrees with previous work on eavesdropping, and extends the evidence for such eavesdropping as a choosy female sexual strategy across species.