World / Science & Health

Bowhead whales improvise when singing

AP

Some whales are taking jazz riffs to new depths.

For the first time, scientists have eavesdropped year-round on the songs of bowhead whales, the little-heard whales that roam the Arctic under the ice. They found that bowheads — the bigger, more blubbery cousins of the better-known humpbacks — are more prolific and downright jazzier than other whales.

“Bowhead whales are the jazz singers of the Arctic. You don’t know what they’re going to do. They inject novelty,” said University of Washington oceanographer Kate Stafford.

Over three years, a single underwater microphone captured 184 distinct bowhead whale songs, according to Stafford’s study in Wednesday’s Biology Letters. That is remarkable especially because there are probably only a couple of hundred males in an area between Greenland and Norway to make the songs, Stafford said.

Stafford and her colleagues couldn’t track specific songs to individual whales to know for sure. But, given the wide variety of songs, they think each male has a different song and the songs likely change from season to season.

In contrast, nearly all humpback males sing versions of the same song every winter, Stafford said. “Humpback whales are classical music singers. They make long elaborate songs, but their songs are really ordered and almost predictable.”

Until now, biologists would hear only snippets of bowhead songs in other Arctic areas. They have many recordings of humpback songs because there are more humpbacks and they travel much farther south.

Scientists think that only male bowheads sing and that they sing for sex, improvising to try to attract females. Stafford said she was reminded of Miles Davis on his “Bitches Brew” album.

She admitted bowhead music isn’t for everyone. “I find the songs to be quite beautiful, but some people compare them to fingernails on a chalkboard,” Stafford said. “They’re screamy. They’re yelly, and they’re quite funny.”

Bowheads — which can live to be 200 years old and are almost 60 feet (18 meters) long — start with very high notes, modulate their tune quite a bit and at times make two completely different sounds at the same time.

“We don’t know how they do that,” Stafford said. Humans can’t, but some birds can.

Syracuse University biology professor Susan Parks, who wasn’t part of the study, praised the research as “a huge step forward” in learning about bowhead songs, showing surprising novelty and variety.

“The diversity of signal types uncovered by this study suggests that something very different is going on with bowhead whale song,” Parks wrote in an email.

One of Stafford’s favorites makes repeated riffs of “woo-woo-woo” but with differing modulations. She will often just turn the songs on her cell phone and bliss out.

“These guys are great mimics. They can imitate ice,” Stafford said. “They make the nuttiest songs.”