Humpback whales found to compose new communal song every few years
A team of researchers from the University of Queensland and the University of St. Andrews has found that humpback whales abandon community songs every few years and pick up new ones. In their paper published in Proceedings of the Royal Society B, the group describes their multiyear study of humpback whale songs and what they found.
Some species of whales sing—humpback whales, in particular, are known for their songs. Interestingly, all male humpback whales sing the same song—though some do make some minor modifications to it. In this new effort, the researchers have discovered that every few years, humpback whales choose to abandon the song they all know, and learn to sing a new one. The research team made this finding by conducting a study of whale songs over the course of 13 years—listening in on humpback whales singing off the eastern coast of Australia and in the South Pacific.
The researchers noticed that a new song would start out as a simple tune that would grow in size and complexity over time, eventually reaching a point at which it became ungainly. Some new group of whales would eventually abandon the song and come up with a new one, which they carried with them as they migrated to other parts of the ocean. Along the way, other whales would hear the song and abandon the old one, as well. Eventually, all the humpback males would be singing the same new tune.
The researchers still cannot say for sure why the whales sing, though it is tied to the breeding season, or why they change their song every few years. They suspect it is because the song grows too complex, suggesting a cap on a learning curve—though it is possible the whales simply grow bored with it. The researchers note that social singing by the whales is an example of animal culture. And learning about animal culture could perhaps lead to a better understanding of how complex human culture evolved. They also note that the kind of cultural transmission seen in the whale songs has only ever been observed in humans.
More information: Jenny A. Allen et al. Cultural revolutions reduce complexity in the songs of humpback whales, Proceedings of the Royal Society B: Biological Sciences (2018). DOI: 10.1098/rspb.2018.2088
Journal information: Proceedings of the Royal Society B
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