Researchers Document Rare Sperm Whale Birth, Find Evidence of Cooperative Behavior

A team of scientists with Project Cetacean Translation Initiative published the most detailed record of a sperm whale birth last month, offering the first quantitative evidence that non-primates assist one another in giving birth.

The group — which spans more than ten institutions, including the Harvard School of Engineering and Applied Sciences, the University of Oxford, and the University of California, Berkeley — published its findings from six hours of underwater audio and aerial drone footage captured in 2023 off Dominica, a Caribbean island.

The researchers were following a unit of sperm whales spanning three generations of related and unrelated females when they observed one of the whales giving birth in July 2023 — an event documented in fewer than 10 percent of marine mammal species. The team was led by Project CETI’s lead biologist, Shane Gero.

“It was an unimaginable day,” Gero said. “When the blood happened, I thought it was a predator that had attacked, not a birth. And then a little head popped up and we knew exactly what was going on.”

Witnessing a whale birth is unusual, according to SEAS professor Roger J. Wood, one of the paper’s co-authors. Sperm whales rarely aggregate at the surface for long, diving instead to hunt in the deep ocean, and the stretch of sea researchers can cover at any one time is small.

“Artemis recently reminded us of how huge the world is, despite being a speck in the universe,” Gero said. “If you put dozens of research boats driving around in the ocean, and thousands of sperm whales swimming around the ocean, the probability that two of those things happen in the same place is just low.”

The researchers then observed an even rarer event: other whales in the unit coordinated physical support for the mother after the birth, exhibiting caregiving behaviors the team said had rarely been witnessed in marine mammals.

Two drones were in the air and a hydrophone was in the water during the birth, and the audio data showed distinct shifts in the whales’ sounds. The team also took photographs and recorded behavioral observations from the boat. The findings were published in Science and in Nature’s Scientific Reports in late March.

Daniel Vogt, the project’s lead SEAS engineer, said the team’s ability to capture the birth in such detail was partly a matter of chance.

“We had some luck on our side to just be there at the right time, at the right moment, to assist this event that really doesn’t happen every day,” Vogt said in an interview with The Crimson.

Project CETI is primarily focused on collecting data to understand sperm whale communication. Vogt said the Harvard researchers were chiefly interested in pioneering the technology to capture the underwater audio itself — including tags that suction to the whales and record audio, depth, and GPS data for nearly 18 hours.

The group also used the study to examine the behaviors that allow sperm whales to live in cooperative societies, unlike most other whale species, which live independently. Gero said the footage captured “tiny little stories” of unrelated individuals helping in the birth — interactions he said help sustain that cooperative society.

Wood said the project is now returning to its primary focus: collecting “more and better data” to support machine learning and linguistic research on whale communication. For his lab at Harvard, that means developing smaller and more resilient tags and testing autonomous drones that can attach them to the whales.

SEAS professor Stephanie Gil, a co-author on the Scientific Reports paper, said she was optimistic about the role of machine learning in understanding non-human communication.

“With the progress of ML tools recently, it kind of gives us the space to dream and wonder if we can understand human communication much better now, then can we kind of transition to non-human species communication,” Gil said.

She said new technologies are allowing researchers “to understand the data that we’re gathering in ways that were not possible before.”

Gero said the study’s focus on cooperation carried a lesson for humans as well.

“I think it’s also a really important message at a time in history where we’re not getting along as humans, to sort of learn from someone who’s fundamentally different from us,” Gero said. “When there’s a big challenge, we survive better by working together, even if we’re different, even if we’re unrelated.”