Click on the graphs to listen to the sounds

Killer Whale Bioacoustics

Killer Whales are unique among mammals in that they are one of the few mammalian species which shows true dialects (i.e. social groups making different vocalisations in spite of being in acoustic contact).

The basic social unit of killer whales is the matrilineal unit, consisting of a female, her offsprings, and often a third generation. The dialect of each such matrilineal unit consists of a characteristic and unique set of calls. Most matrilineal units possess at least some calls which are unique to its members, but may share others with other, related, matrilineal units. However, such shared calls usually exist in several distinct versions, one for each matrilineal group which makes it.

Above is an example of such a shared call, the N4 call as made by 9 different matrilineal units of the Northern Resident Community inhabiting the coastal waters of British Columbia. On the left hand side you see spectrograms of the groups' versions of the N4 call. Click on the graphs to listen to the sounds.

The acoustic phylogeny on the right hand side was generated by training an artificial neural network to discriminate between 24 N4 calls of the different groups. Groups which link in the yellow have relatively similar calls, and the neural network could not tell them apart consistently, groups which link in the red are acoustically distinct, and gave good discrimination.

Spectrograms were made using Canary 1.2 and MATLAB.

Note: you will require a sound application capable of reading files in AIFF format to listen to the killer whale calls. If you don't have such software, click the following to: Please be sure to pay the registration fee if you decide to keep the software!

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A08-N4 and A11-N4 © John Ford, A09-N4 and A25-N4 © OrcaLab, A12-N4 and A30-N4 © Frank Thomsen, A23-N4 © Dave Briggs, A24-N4 © Steve Wischniowski , A36-N4 © Volker Deecke