Sex differences in song perception in Bengalese finches measured by the cardiac response

Birdsong may be perceived and processed differently by males and females because the production and function of this behaviour are often sexually dimorphic. However, examination of this hypothesis has been difficult, since different behavioural measures have been used to describe the perceptual process for each sex. We analysed changes in heart rate as an index of song perception in Bengalese finches, Lonchura striata var. domestica. In this species, only males sing, and song is used exclusively for mate attraction. This species is not territorial and songs are never used in aggressive contexts. In both sexes, repeated presentation of a song resulted in a waning of the heart rate response. Presentation of heterospecific songs did not increase the heart rate. When a novel conspecific song was presented, the heart rate increased only in females with each presentation of the stimulus, not in males. These results correspond to the sex differences in song usage in this species.