DJ Humpback: Whales remix their old songs
Humpback whales are famous for their complex and mysterious songs, and scientists tuning into their sounds off the coast of Australia have discovered the interesting way in which they acquire these singing skills. The research reveals that humpback whales learn songs in segments, just like the verses of a human song, and because of this they can mix the old with the new just like your favorite DJ.
The research was led by Dr. Ellen Garland, a graduate from the University of Queensland who drew on data gathered by the School of School of Veterinary Science's Cetacean Ecology and Acoustics Laboratory (CEAL).
The team set out to learn more about how humpback whales use song as a form of social learning, where cultural traits are passed from one to another rather than passed down through the generations. This meant drawing on more than 9,000 recordings taken in the South Pacific Ocean, with the scientists focusing on whale songs that were in the process of changing from one type to another.
"We recorded many individual singers from several populations, including the eastern Australian population and other populations in the South Pacific," says Associate Professor and study co-author Michael Noad. "We looked for songs that were caught in the act of changing; songs that had some of the old song as well as some of the new song."
The team found that the whales appeared to learn songs in a similar way to how humans learn language, segment by segment. This means that they could combine "verses" of songs, mixing parts of older songs in with newer songs, and they did this in a couple of ways.
One was by combining verses from old and new songs and using that hybrid phrase as a transition between the two. The other was by slotting in a complete verse from one song into another. Most impressive is that these both occurred at points in a song where both tunes contained similar sounds arranged in similar patterns (known as themes), just like a master DJ making a seamless transition.
The researchers say that whale songs are one of the most striking examples of social learning in non-human animals, and that this newly discovered baleen beat-matching could even help inform our understanding of how us humans came to communicate.
"The other interesting thing was when they switched mid-song from old to new or new to old, it was during a theme most similar to another theme in either old or new songs," says Noad. "These themes may have been used as a way of bridging the old and new songs and therefore help with social learning. This provides some evidence for how animals rapidly learn large, complex displays and may have relevance for understanding how human language, the most outstanding example of social learning, evolved."
The research was published in the journal Proceedings of the National Academy of Sciences.
Source: University of Queensland