Rapid vocal convergence in an Australian cockatoo, the galah Eolophus roseicapillus

There are several mechanisms for producing vocalizations that are similar to those of a conspecific, including song type matching during a vocal contest, group convergence on a signature call over time, or one-to-one matching of another individual's signature call. A novel category of conspecific matching has been described in a parrot, the orange-fronted conure, Aratinga canicularis, which shows rapid and directional modi. cation of vocalizations over the course of a single vocal interaction. We examined whether a geographically and phylogenetically distant parrot, the galah, Eolophus roseicapillus, uses similar rapid call modi. cations during contact call exchanges, and sought to better de. ne the conditions under which wild parrots directionally modify their contact calls. In each trial, we interactively broadcast a single call exemplar recorded from wild galahs and recorded the vocal responses of nearby galahs. Temporal parameters of response calls converged on the stimulus over the course of an interaction. Frequency measures also showed convergence, although this effect was less pronounced. Male galahs were more vocally responsive overall, and birds tended to converge more closely on male stimuli over the course of an interaction. This experiment confirms that other parrots, in this case galahs, are capable of rapid, directional call modi. cation, and we suggest that this vocal technique may be an efficient mechanism for mediating the fission-fusion social system that is characteristic of many parrot species. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.