Acoustic Communication of the Killer Whale, Orcinus orca

Abstract

Functional use of killer whale pulsed calls is an important facet of their communication. The complexity of their vocalizations presents opportunities for theoretical and structural analysis of such calls. This study seeks to answer questions regarding social and behavioral context of monophonic and biphonic calls, how they can be classified using computer science technology, and what possible mechanisms for sound modulation exist anatomically in varying populations of Orcinus orca. The method used to guide this review is described by Arksey and O’Malley as the scoping review method (Pham et al., 2014). All research included in this review is organized into a data table for reference. Features of killer whale communication were broken down into multiple definitive groups including clicks, whistles, pulsed, discrete, aberrant, variable, monophonic, and biphonic calls. Computer network analysis of the vocalizations has provided a framework for comparing and classifying both similar and dissimilar calls. Restricted study of the anatomy of vocal producing organs in this species has limited true understanding of both sound generation and the extent of vocal manipulation, but distinct biological structures have been identified and their significance discussed. Concrete conclusions over niche usage of calls in killer whale society have not been made, however, it is known that most calls are too complex to only be associated with a singular behavioral or social context. Rather, their complexity has furthered the need for additional research to be conducted.