Responsiveness of a male Mueller's gibbon to his own species-song,that of a lar gibbon,and a synthetic song of similar frequency

The study compared the responsiveness of a captive male Mueller's gibbon to audio recordings of dawn songs of wild-living male Mueller's gibbons and lar gibbons, and to a synthetic song constructed from screech owl vocalizations. Though wild-caught, the subject had not been exposed to songs of his own species for at least 10 years, and in fact, only rarely performed the dawn song himself. Initially, the subject responded vigorously to all three recordings, with no preference being shown for the recording of his own species. However, a very strong preference for Mueller's vocalizations did develop following a period of concentrated and exclusive exposure to Mueller's songs.