Meet the Louis Armstrongs of the Arctic Ocean
“We heard hours and hours and hours of singing from these whales, from November up until early April.”
Bowhead whales, it turns out, are the jazz singers of the ocean.
That’s the conclusion of Kate Stafford, an oceanographer with the University of Washington, who has been studying the singing of bowhead whales off the northeast coast of Greenland with the help of underwater microphones.
Her latest findings, published in Biology Letters, a journal of the United Kingdom’s Royal Society, describes the surprising variety of music being produced by the bowhead population in Fram Strait throughout the depths of Arctic winter between 2010 and 2014.
“We were just astonished,” Stafford said in an interview with Nunatsiaq News. “We didn’t hear just a few sounds; we heard hours and hours and hours of singing from these whales, from November up until early April.”
Sound is the most important sense for all marine mammals—especially those that live in Arctic waters that are ice-covered and dark for much of the year. As Stafford says, “they use sound to navigate, to find food, to communicate, to keep in contact with each other.”
Yet not all whales sing. Belugas may be able to produce complicated clicks, whistles and squeaks, but whale experts contend that the only real singers are some baleen whales.
Baleen are plates made out of keratin—the same substance our fingernails are made from—which hang from the roofs of these whales’ mouths.
These whales suck up vast quantities of water and then spit it back out, using the baleen to strain out any tiny critters, such as krill and copepods, to eat.
“Bowhead whales are the only baleen whales to live in the Arctic year-round. And, of the baleen whales that sing, it’s really only the humpbacks and the bowheads that make loud, long, elaborate, variable songs,” Stafford said.
“Other whales that are known to sing include blue whales and fin whales, but their songs are much simpler. They stay the same between years. So it’s a very different thing from what humpbacks and bowheads are doing.”
What’s more, only male whales are believed to sing. It’s suspected they do so to attract a mate.
“It’s a behaviour that happens during the mating season, which for all these mammals is the winter,” said Stafford. As well, she adds, this is consistent behaviour with other species, “like mice and bats and frogs and birds.”
It turns out the musical styles of humpbacks and bowheads are much different—which is why Stafford says “humpback whales are classical musicians while bowhead whales are jazz singers.”
“For a humpback whale song, all the males in one population will sing the same song in a year. It may change a bit as the year goes on, but by and large all the males adopt the same changes. And the following year, the humpbacks will sing a different song, but they’ll use many of the same phrases as they used before.
“And humpback whale songs—they’re quite beautiful and interesting, but they’re very ordered. They make notes that are formed into phrases that make themes that are put together into a song. It’s much like movements of classical music.”
Bowhead whales, meanwhile, seem to favour musical improvisation. “They change songs within a year,” said Stafford. “In Fram Strait, for instance, we recorded dozens of different songs every winter. And the surprise of this study is that we’ve never recorded the same song in two different years.”
The study also helps confirm that Fram Strait is important habitat for bowhead whales. “Every year we’ve eavesdropped, we’ve heard loud, abundant, extensive bowhead whale singing,” said Stafford. “So that says to us that Fram Strait is probably critical habitat for this population.”
Another question the study sought to answer is whether the same songs could be heard in multiple years, “because that might tell us whether individual whales, or groups of whales, have their own song,” said Stafford.
“And the answer is no. Because while every year we’ve heard dozens of songs, within years we’ve never heard the same song twice. So they’re constantly innovating. That gets back to my idea of them being jazz singers. The sounds they can make are spectacular.”
It’s unclear, for now, whether the variety of songs recorded in Fram Strait is typical for bowhead whales, or something particular to the small local population, which is also known as the Spitzbergen population, after the nearby Norwegian archipelago.
“The Spitzbergen whales were the first population of bowhead whales to be commercially exploited, and they were commercially extinct by the 1700s,” said Stafford.
“Ten years ago, we thought there were just 10 Spitzbergen bowhead whales, but work by my co-authors and colleagues at the Norwegian Polar Institute, who have been wonderful about getting the hydrophones in and out every year, they’ve recently found there may be 300 individuals now in the Spitzbergen population—which is not a lot, but is more than tens.”
Canada’s eastern and western Arctic, meanwhile, are home to “orders of magnitude bigger populations” of bowhead whales, said Stafford.
While many questions remain unanswered about the behaviour of bowhead whales, Stafford says the latest findings just add to a long list of the species’ remarkable traits.
“They can live two human lives,” she said. “They can break up to half a metre of ice with their head. They’ve got the thickest blubber and the longest baleen of any whales. And they sing these incredible songs. They’re truly these ice whales. And they’re the only large whales to live in the Arctic year-round. So they’re just superlative animals.”