When the terrestrial ancestors of whales took the plunge and moved into the ocean, around 50 million years ago, they developed all sorts of adaptations for their new aquatic lives.
They evolved nostrils on top of their heads, making it easier to breathe at the water surface, and their limbs morphed into flippers and fins for swimming. Although people have known for a long time about the songs of humpbacks and other baleen whales, until recently it remained a mystery how they made these sounds.
Studying the voices of living whales while they’re roaming the ocean is a huge challenge. In a groundbreaking study published in early 2024, scientists took the rare opportunity to examine the voice boxes, or larynxes, of three baleen whales — a humpback, sei and minke whale — that had washed up dead on beaches, but were not too badly decomposed.
The larynx of baleen whales is a unique organ consisting of long cylinders connected into a rigid U-shape that pushes against a fatty cushion. When scientists blew air into the larynx, they found that this makes the cushion vibrate and generate low-frequency sounds.
Living whales recycle air through their larynx, which means they can make sounds without choking on water or exhaling precious air. Researchers also built a 3D computer model of the whale larynx and simulated how the sounds are controlled by muscles.
This showed that baleen whale songs overlap in frequency with the noises produced by ship propellers.
The structure of their larynx means the whales have no way of adjusting the pitch of their voices to avoid clashing with underwater sounds made by vessels, making it difficult for them to hear each other over long distances in the increasingly noisy ocean.
This article is an answer to the question (asked by Howard Hinchcliffe, via email) 'How do whales sing under the sea?'
To submit your questions, email us at questions@sciencefocus.com, or message our Facebook, X, or Instagram pages (don't forget to include your name and location).
Check out our ultimate fun facts page for more mind-blowing science.
Read more: