The function of double chees in orange-fronted conures (Aratinga canicularis; Psittacidae)

Orange-fronted conures use individually distinctive contact calls (chees) to mediate social interactions. During vocal exchanges, individuals are known to imitate each other's contact calls. Chees are most often given singularly, but also occur in doublets, known as double chees. We used interactive playback to assess the function of double chees in imitative contexts. By using stimuli with varying levels of similarity between the chees within a double chee, we found that wild-caught conures held for short periods in an aviary imitate the second chee of the double chee more than the first chee. This suggests that the more relevant information in mediating the exchange is contained in the second chee, and the first serves some alternative function. Double chees do not increase the overall intensity of an interaction, nor do they improve the overall accuracy of imitation. However, double chees may serve a role in signaling and directing changes during chee exchanges.