Whales can hone their singing skills by practicing in the off-season

Human musicians must practice for thousands of hours to perfect their performance skills, and the same can be true for humpback whales.

It is widely believed that male humpbacks (Megaptera novaeangliae) sing to attract mates, but zoologists have recently realized that they also sing at high latitudes feeding grounds, months before they migrate to the low-latitude breeding grounds where they mate with a mate.

“We’re drowning in song,” says Erin Wall of the Raincoast Conservation Foundation, a non-profit group based in British Columbia, Canada. Since September 2023, she has used a network of 17 underwater microphones on the province’s Pacific coast to record and pollinate the songs of feeding males throughout the summer and fall. These males migrate to Hawaii and Mexico during the winter and spring breeding season.

She observed in her fieldwork and two years of recordings that the song is very rare in the summer, probably because males are busy eating. But then the song begins to “ramp up,” starting with short, playful fragments that are 3 to 4 minutes long in September and getting longer throughout the season.

In December, the songs are extended to 10 to 20 minutes. This is consistent with the little research that exists on feeding grounds elsewhere in the Northern Hemisphere, namely Atlantic Canada.

“I think it’s when they learn that song that they will eventually perform on their breeding grounds,” Wall says.

Her research suggests that after a summer hiatus, the males slowly reconstruct their song from the previous breeding season in anticipation of the next one. And since all the males in a population sing essentially the same song, with the odd personal flourish, she expects these feeding ground rebuilding efforts to be somewhat cooperative. Basically, she says, they practice.

In addition to the songs getting longer, Wall has also noticed a progression in the song structure as the season progresses. “Early in the season, there’s a lot more entropy, I would say. A lot more variety,” she says. “Then as you get later in the fall, these very clear themes emerge where you get these repetitive phrases that become more and more frequent, more stereotyped.”

Wall presented his preliminary findings at the Society for Marine Mammalogy conference in Perth, Australia, in November and hopes to publish them soon.

Despite decades of research, we’re still not entirely sure why humpbacks sing at all. “It seems that the more we learn, the less likely our early ideas are correct,” says Jim Darling, a zoologist at the Whale Trust Maui in Hawaii, who studies whale songs across the North Pacific.

Despite its enduring popularity, Darling says the idea that men sing to attract women has never been consistent with observation. He has spent time with hundreds of males who supposedly serenaded around the water, and the only companions they ever attracted were other males who came together for brief duets before parting ways. If a woman is in the presence of a singing man, it is generally because he addressed her, after which she is apt to swim away mid-performance.

Wall’s hypothesis seems viable and exciting, says Darling. “There is much that is not known about singing and singing behaviour, and this is especially true [on feeding grounds]so the canvas is wide open, so to speak, and possibly hypothesis – as long as this term is emphasized – which can explain observations is, in my opinion, legitimate.”