The complex acoustic repertoire of a highly social species the Noisy Miner Manorina melanocephala

Abstract

Communication is an essential component of social interactions between individuals, particularly in larger group sizes. To gain further insight into the factors that underpin cooperative behaviour, herein we examine the acoustic repertoire of the Noisy Miner, Manorina melanocephala, a cooperative species that lives in large colonies. To determine the structure and composition of the Noisy Miner repertoire, we measured the call rates and major acoustic parameters of common vocalisations from colour-banded individuals located at two discrete colonies. A total of 13 different vocalisation types were identified, of which 3 are newly described, with an additional 10 vocalisations being quantified in a new social context. Importantly, we describe a call given only by females and document both sexes producing some calls that were previously thought to be sex-specific. The putative repertoire identified was supported by statistical assessments confirming differences in their spectral and temporal features. Vocalisations were given across a range of social contexts, including the mobbing of predators, aerial alarm vocalisations, apparent maintenance of group cohesion and advertisement of individual location and/or status. This study quantifies the rich vocal repertoire of this social species, and provides further implications for the link between cooperative breeding and large vocal repertoires.