Data set: The origin of sex differences in song in a tropical duetting wren

The study of song development has focused on temperate zone birds in which typically only males sing. In the bay wren, Cantorchilus nigricapillus, both sexes sing, performing precisely timed, female-initiated duets in which birds alternate sex-specific song phrases. We investigated the origin of these sex differences by collecting bay wren eggs and nestlings and hand-raising them in individual acoustic isolation chambers. Each bird was tutored with either monophonic or stereophonic recordings of bay wren duets, or heard no song. As adults, each tutored bird individually sang complete duets, singing both male and female song phrases. On occasion, birds learned only the male or female part of a duet to which they were exposed. However, mono-tutored birds showed no sex-specificity in these solo songs, whereas stereo-tutored birds only sang solos consistent with their sex. In addition, stereo-tutored birds acquired songs over a longer period than did mono-tutored birds. In both groups, fema...