Arctic Bowhead Whales Communicate by Singing Haunting 'Jazz'

When you think of great jazz artists, bowhead whales are probably not the first thing that come to mind.

But a new study conducted by a team from the University of Washington (UW) analyzing audio recordings of bowhead whales in the Arctic has shed light on this mammal's extraordinary songs, which the scientists have compared to freeform "jazz".

The UW team gathered the audio from underwater microphones—known as hydrophones—between 2010 and 2014 off the east coast of Greenland, finding an incredible variety of 184 different songs in a population of around just 200 individuals, according to the study published in the Royal Society's Biology Letters.

Nearly all mammals communicate using sound, but only a handful of species actually produce complex songs like those found in the bowhead whale. Animal songs differ from other types of animal calls in the sense that they are complex and distinct musical phrases that must be learned.

"If humpback whale song is like classical music, bowheads are jazz," Kate Stafford, an oceanographer at UW's Applied Physics Laboratory and lead author of the study, said in a statement. "The sound is more freeform. And when we looked through four winters of acoustic data, not only were there never any song types repeated between years, but each season had a new set of songs."

The new findings indicate there is a healthy population in the area despite the fact that the bowhead whale is critically endangered.

Stafford has been researching whale vocalizations for more than a decade as a way to track and study marine mammals. In a 2012 study, she recorded bowhead whales off Greenland's west coast singing continuously during the winter breeding season, indicating there was also a healthy population there.

"We were hoping when we put the hydrophone out that we might hear a few sounds," Stafford said referring to the previous study. "When we heard, it was astonishing: Bowhead whales were singing loudly, 24 hours a day, from November until April. And they were singing many, many different songs."

The new research builds on this earlier work and reveals that bowhead whales in this region sing relentlessly from late fall to early spring, using an amazing diversity of musical phrases. The study also confirms that these songs are completely different from those of humpback whales—the only other whale that's known to sing complex songs.

It is a still unclear to researchers why the bowhead whales sing these songs and, in particular, why the melodies constantly change. But scientists do know that marine mammals rely on acoustics to navigate, find food and communicate in other ways, such as identifying themselves as individuals or members of a group.

And it's possible that, like birds, the songs may be used to compete with others and attract mates, the researchers suggest.

"Bowheads are superlative animals: they can live 200 years, they've got the thickest blubber of any whale, the longest baleen, they can break through ice," Stafford said. "And you think: They've evolved to do all these amazing things. I don't know why they do this remarkable singing, but there must be a reason."