How canaries listen to their song

Abstract

Canaries have become important models for the study of vocal learning. The male produces long song bouts up to a minute long consisting of various syllables, each repeated in flexibly sequenced phrases. Little is known about how the birds listen to song though behavioral observations clearly show that female canaries are more sexually responsive to a special song element—so called “sexy” syllables—which are distinguished by a high syllable repetition rate, wide-bandwidth, and multiple notes. Here, operant conditioning and psychophysical techniques were used to determine the discriminability of variation in syllable and phrase morphology. Results show that canaries can discriminate the subtle differences among syllables and phrases using spectral, envelope, and temporal fine structure cues but they are no better than budgerigars used as controls. There was also evidence that perception of sexy syllables is distinctive for canaries. On the whole, while canaries can hear the fine details of the acoustic structure of their song, the evidence suggests that they listen at a more synthetic rather than analytic level. These results give clues to how the canary perceptual system may be shaped to process male song and make judgments about mate quality.