The Ways of Whales workshop today was successful, with over 100 people in attendance. There were some great talks: Brad Hanson talked about satellite tagging, John Calambokidis talked about new insights into North Pacific baleen whale stocks, a former Sea World trainer gave her views on last year’s tragic death of a trainer, and Suzanne Chisholm shared a project she is working on about the dolphin captures in Taiji. The lecture I gave was about killer whale acoustics, including some background on call usage and also tips for listeners on how to figure out which pod they are listening to when they hear the whales on the streaming hydrophones at www.orcasound.net.
One other bit of information I shared was about a study I got to participate in last year that resulted in a paper that was just published by Nicola Rehn and colleagues in a natural science journal journal*. When I was contacted by a colleague of mine, Andy Foote, last year, he asked me to listen to several dozen orca calls and place them into categories based on how I thought they should be defined.
After I went through all of the calls and organized them into call types, he told me what the study was about: they believe that there is an orca call, that they’ve termed V4, which is universal across not only different killer whale populations, but different killer whale ecotypes (resident, transient, offshore). Indeed, I had placed all of the proposed V4 calls into the same category, even though they came from five different populations of whales: the Southern Residents, the Northern Residents, the Kamchatka Residents, the Pacific offshores, and the Bering Sea transients. Eight other independent observers came up with similar classifications, justifying the researchers’ belief that this may be a universal call type.
This finding is interesting for two reasons. First of all, it’s the first demonstration of an overlap of call types between different populations of orcas that until now were believed to have completely distinct dialects. Second of all, the calls are primarily recorded in high excitement states, regardless of the population the call came from. For the residents and offshores, the call occurred in social situations, and for the transients, the call was recorded after the group had made a kill. The evidence points to this being an innate, universal call type that is highly variable but still categorizable – much like human laughter or crying.
The V4 call is often heard among Southern Residents and was termed S10 in the 1980s by John Ford. I’ve always described this call to others as sounding like the whales are laughing, and it turns out this may not be so far off! Here’s a sample of the call so you know what to listen for if you’re tuning in to the hydrophones:
*More information can be found in the paper: Rehn et al (2011). “Cross-cultural and cross-ecotype production of a killer whale ‘excitement’ call suggests universality”. Naturwissenschaften. (98):1-6.