Australian killer whales (also known as orcas) have been given a voice thanks to a dedicated research team from Curtin University’s Centre for Marine Science and Technology (CMST).
The study, led by PhD candidate Bec Wellard and CMST Director, Associate Professor Christine Erbe, took the team into the Bremer Canyon off the south-west coast of Western Australia, where they recorded the sounds from killer whales.
“To date, there has been no dedicated study on killer whale acoustics in Australia due to their transient nature which makes killer whale research difficult using conventional methods,” Ms Wellard said.
Deputy Vice-Chancellor Research and Development Professor Graeme Wright said the research was an excellent example of how Curtin University contributes valuable and practical scientific knowledge to Australia.
“This examination will provide a much needed foundation for future research into a species that clearly inhabits our waters yet about which surprisingly little is known,” he said.
Associate Professor Erbe explained a detailed description of the acoustic characteristics was necessary for the identification of the killer whales.
“CMST’s expertise is in passive acoustic monitoring of the marine ecosystem, and we have been listening to the Australian marine soundscape for two decades,” Associate Professor Erbe said.
“Once we have characterised the call repertoire of Australian killer whales, we can very efficiently and at minimal cost monitor their distribution around the continent.”
The study will institute a basis for comparison of the acoustics of other killer whale populations worldwide and uncovering potential distinctive repertoires in the Australian population.
Killer whales live in groups known as pods, and in the northern hemisphere, where the species has been studied at a much greater level, pods have been known to develop their own dialects.
They communicate using burst-pulse sounds and whistles, and they echolocate (much like a submarine sonar system) using click-trains. The Curtin research team was able to monitor these sounds using a passive acoustic technique to help uncover how the Australian killer whales interact in a range of contexts including socialising, travelling and hunting.
Curtin Research Associate, Leila Fouda, part of Curtin’s Team Orca, is leading a study on killer whale ecology. This project has a citizen science component, and the public is able to contribute information on killer whale sightings at http://surveynuts.com/code, entering the code KW15.
It is hoped both research projects will lead to further discoveries about the little-known down-under orcas.
The acoustic study has been published today in respected scientific journal PLOS ONE and can be viewed online at http://dx.plos.org/10.1371/journal.pone.0136535.
Associate Professor Christine Erbe and researcher Leila Fouda received partial funding from the SeaWorld & Busch Gardens Conservation Fund.