Every year a new catchy pop tune spreads among the male underwater crooners, said an Australian study on humpback whales.
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WASHINGTON: Humpback whales love a good hit single, an Australian researcher has reported, finding that the males 'change their tune' every year during their migration across the Pacific.
In the study, 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. The results reveal a striking pattern of cultural change over a large distance, with the rate, scale and repetition unmatched in non-human culture.
"I noticed that the songs moved quite rapidly through the six populations, usually taking two years to spread all the way across the region," lead author Ellen Garland from the University of Queensland 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."
Infectious tunes travel east
According to Garland, that the songs had spread across whale populations suggests acoustic contact or male dispersal between populations in the region. The males were the only ones found to sing, possibly as a kind of courting behaviour.
"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," said Garland of the research published in Current Biology.
A whale's hit-making tune ripples eastward across the South Pacific Ocean, from Australia to French Polynesia, infecting genetically distinct groups of whales who all start singing the same song during breeding season, the paper reports.
Not the most original tunes
The males in a population were observed to sing a similar song, but it was continually changing and evolving over time, and were not all that original.
"It would be like splicing an old Beatles song with U2," said Garland. "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."
Quest for song novelty
The 11-year study is the first documentation of a repeated, dynamic cultural change occurring across multiple humpback whale populations across a large geographical scale.
What remains a mystery is why the whales all sing the same song, when presumably their efforts are meant to make them stand out against the pack.
"We think this male quest for song novelty is in the hope of being that little bit different and perhaps more attractive to the opposite sex," said Garland. "This is then countered by the urge to sing the same tune, by the need to conform."
