Cultural diversification in the flight call of the Ringneck Parrot in Western Australia

I investigated geographic variation in a parrot vocalization to obtain an u nderstanding of cultural population differentiation and exchange between hy bridizing taxa. The flight calls of Ringneck Parrots (Barnardius zonarius) were tape recorded in Western Australia within and outside the zone of over lap and hybridization between the Port Lincoln (B. z. zonarius) and Twenty- eight (B. z. semitorquatus) subspecies. Measured variables distinguished th e Twenty-eight call from those in the overlap populations. Although birds i n typical Twenty-eight plumage were present in the overlap zone, no Twenty- eight flight calls were found, suggesting convergence by immigrants. Popula tions within the hybrid zone also were acoustically differentiated as diale cts associated with roosting areas. Observations on the social behavior of the birds indicated that this call functions in coordination of movements o f the mated pair. Roost-specific dialects might aid pairs in finding each o ther in the event of separation during the day's foraging activity.