African parrot vocalizations and their functional significance

Parrot vocalisation is a very complex bioacoustic subject even to those bio logists who are familiar with songbird analysis. This appears to be related to the great semantic complexity of vocal communication of these birds. Th erefore,the detailed description of vocalisations appears to be crucial for future analysis of Parrot communication. Since 1993, we started to investi gate different aspects of both learned and innate vocalisations of African Poicephalus Parrots. In this paper, we review these studies to summarise th e following findings potentially useful to the study of Parrot communicatio n: (i) Duets: in the Red-fronted Parrot Poicephalus gulielmi, the complexit y of the duet is a function of the stability of the pair bond; the song con vergence increases with the length of time that the pair has previously spe nt together and duet complexity is learned and refined over time; (ii) Iden tification motif we studied the nest interactions between parents and chick s in Meyer's Parrot (Poicephalus meyeri). We found that identification moti fs are developed which are peculiar to an individual and function as a way of identifying the individual to its family group; (iii) Food begging call: we describe the ontogeny and possible fate of food begging calls in 5 spec ies of Poicephalus Parrots. This call has a pulsing structure and the numbe r of pulses is reduced with time. The final outcome of the develop-mental p rocess from the innate food begging call seems to be the learned contact ca ll of adults; (iv) Distress call: the distress call of African Poicephalus Parrots is a sexually dimorphic vocalisation, with significant differences in the main physical parameters of the two sexes of all the species studied . We also found significant differences between species and superspecies ev en though this vocalisation is extremely conservative.