Humpback valves, known for their exact rhythmic sound patterns, sing the same songs for a few years before decorating them to make them more complicated. According to the University of Queensland research, after a few years, the whales change to newer simpler songs that show their ability to learn new material.
The study, published on November 21, in the journal Proceedings of the Royal Society B: Biological Sciences, studied the structure and complexity of songs sung by Australian humpback whale populations for 13 consecutive years. The Pukkelval singers were recorded every year from 2002 to 2014 in southeastern Queensland, Australia, using fixed hydrophone sets, autonomic recorders and boat-based recordings.
The researchers found that although the songs sung by the whales gradually change each year, the whales completely replaced their songs with new each year in which researchers called a "cultural revolution".
"Complexity increased when songs were developed, resulting in longer songs with more audio devices, device types and themes. After revolutions, complexity reduced so that new songs were shorter and contained less units, device types and themes," the study says.
"Usually these songs were gradually changed, possibly by decorating individual singers," says Dr. Jenny Allen from the University of Queensland's Cetacean Ecology and Acoustics Laboratory, the main author of the report, in a press release of 22 November.
"We suspect the ornaments allow bulls to stand out from their peers, just as teenage boys try to stand out from the crowd. But each year the songs are replaced – always with something simpler – indicating that there is a limit for the whales' ability to learn new material, "explains Allen.
The study is a good model for cultural learning in animals, Allen said, adding that the humpback song is spread across populations and animal basins.
"This is cultural transfer on a scale comparable to what we like people," she said.
"By learning more about culture and social learning in animal species like humpback whales, we can gain a better understanding of what led to its development and what evolutionary value it holds. By answering these questions on animals, we may explain why cultural and social development has occurred in such a unique degree in humans, "she added.
All did not respond immediately to Sputnik's request for comments