Humpback whales spread songs across the Pacific

Researchers at The University of Queensland have found that male humpback whales 'change their tune' every year during their migration across the Pacific. A study on whale song published today in the US journal, Current Biology, reveals a striking pattern of cultural change over a large distance, with the rate, scale and repetition unmatched in non-human culture.

UQ PhD student Ellen Garland said 11 different humpback whale song types were identified, which typically started in the eastern Australian population and spread in a step-wise fashion across the region to French Polynesia.

"I noticed that the songs moved quite rapidly through the six populations, usually taking two years to spread all the way across the region," she said.

"This can compare to the game of Chinese whispers, except the song appears to be transmitted with little changes unlike a human sentence in the game."

Ms Garland said songs had spread across whale populations suggesting acoustic contact or male dispersal between populations in the region.

"The reason we believe the song tends to travel east is because the eastern Australian population is the largest in the region and has a greater influence than the smaller Oceania ones," she said.

Previous research has revealed that only male humpback whales sing and that song is a behaviour used in courtship and mating.

Ms Garland said all of the males in a population sang a similar song, but it was continually changing and evolving over time.

"Song can undergo evolutionary change, which occurs over a long period of time, or revolutionary change, where the males start singing a completely new song," she said.

"We believe the song is continually changing because the males wish to be novel or slightly different to the male singing next to them.

"The way whales change their song can be compared to how humans follow fashion trends - someone starts a new trend and before you know it everyone starts wearing the same thing."

The study is the first documentation of a repeated, dynamic cultural change occurring across multiple humpback whale populations across a large geographical scale.

It was undertaken in collaboration with the South Pacific Whale Research Consortium and investigated song similarity over an 11-year period within the South Pacific region focusing on the populations of eastern Australia, New Caledonia, Tonga, American Samoa, the Cook Islands and French Polynesia.

Source: University of Queensland