DISCRIMINATION OF DIFFERENT SOCIAL COMPANIONS IN SPECTACLED PARROTLETS (FORPUS-CONSPICILLATUS) - EVIDENCE FOR INDIVIDUAL VOCAL RECOGNITION

Individual recognition is generally assumed to be a prerequisite for e stablishing and maintaining a complex social system. Indeed, there is good evidence that highly social species have complex systems of vocal communication with individual recognition by acoustic cues. In this s tudy, we provide experimental evidence tl;at vocal class and individua l recognition is present in a non-passerine bird, the spectacled parro tlet (Forpus conspicillatus). Spectacled parrotlets live in a complex system of social relationships. Soon after fledging, the young establi sh close sibling relationships which are important for successful soci alization, pairing and reproduction. In a series of playback experimen ts we tested if spectacled parrotlets use contact calls for vocal reco gnition. The results showed that spectacled parrotlets discriminate be tween the contact calls of different social categories. Adult birds pr eferred to respond to the contact calls of their mates. Subadult indiv iduals recognized the contact calls of their siblings. During the peri od of pair bond formation, the affiliative contacts to the siblings de crease, but the parrotlets continue to respond to the calls of their s iblings. This is the first evidence that vocal sibling recognition mig ht outlast the period of strong sibling interaction and extends into t he period of pair bond formation. In cases of mate loss or divorce, th e acoustic contact to their siblings might facilitate the re-establish ment of close sibling relationships.