Humpback whales, known for their precise, rhythmic patterns of sounds, sing the same songs for a few years before adding embellishments to them to make them more complicated. However, according to University of Queensland research, after a few years, the whales switch to newer, simpler songs, demonstrating their ability to learn new material.
The study, which was published 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 humpback whale songs were recorded every year from 2002 to 2014 on the coast of southeast Queensland, Australia, using fixed hydrophone arrays, autonomous recorders and boat-based recordings.
The researchers found that although the songs sung by the whales gradually changed each year, the whales also replaced their songs with new ones every few years in what researchers called a "cultural revolution."
"Complexity increased as songs evolved, resulting in longer songs containing more sound units, unit types and themes. Following revolutions, complexity decreased so new songs were shorter and contained fewer units, unit types and themes," the study states.
"Typically, these songs changed gradually, possibly through embellishments by individual singers," Dr. Jenny Allen from the University of Queensland's Cetacean Ecology and Acoustics Laboratory, the lead author on the report, said in a press release on November 22.
"We suspect the embellishments allow bulls to stand out from their peers, much like teenage boys trying to stand out from the crowd but every few years the songs are replaced – always by something simpler – suggesting there is a limit to the capacity of the whales to learn new material, "explained Allen.
The study is a good model for cultural learning in animals, Allen noted, adding that the humpback whales songs are distributed across populations and animal basins.
"This is a cultural transformation on a scale comparable to what we find in people," she said.
"By learning more about culture and social learning in animal species such as humpback whales, we can gain a better understanding of what led to its development, and what evolutionary value it holds. By answering these questions in animals, we may be able to clarify why cultural and social development has occurred to such a unique degree in humans, "she adds.
Allen did not respond immediately to Sputnik's request for comment