Anish Moonka@anishmoonka
A newborn sperm whale can’t swim. It starts sinking the second it’s born. If nobody pushes it to the surface, it drowns in mile-deep water.
On July 8, 2023, a sperm whale named Rounder went into labor off the coast of Dominica. Researchers from Project CETI, a $33 million AI initiative out of MIT, Harvard, and Northeastern that’s trying to decode whale language, happened to be there doing routine fieldwork. They had drones in the air and underwater microphones running. What they captured over the next six hours just got published in two papers, one in Science and one in Scientific Reports.
Eleven whales gathered at the surface before Rounder even started delivering. Her mother, Lady Oracle, was there. So was her daughter Accra. Three generations in the water. But the wild part: half those whales belonged to a completely separate bloodline that normally keeps its distance from Rounder’s family. On a typical day, these two family lines split off to hunt in different areas and rarely cluster together. For the birth, they all converged before labor started. The unrelated family somehow knew it was coming.
The delivery took 34 minutes. Sperm whale calves come out tail-first with their flukes still folded from the womb. They haven’t developed the oil-filled organ in their heads that helps adult whales float, so the moment they’re born, they’re dead weight in the ocean. Every adult whale in the group, related and unrelated, started taking turns pushing the calf up to breathe. They kept this rotation going for three hours. When a pod of pilot whales (known to be aggressive toward sperm whales) and a large group of Fraser’s dolphins showed up during delivery, the adults formed a wall around the newborn until the threat passed.
The underwater audio is where it gets interesting. CETI’s microphones picked up the whales changing their vocal patterns during the birth. The click-based sounds they use to talk to each other shifted at specific moments, and vowel-like structures appeared in the recordings. This builds on what CETI found in 2024 when they ran machine learning on over 8,700 recorded whale calls and discovered sperm whale communication isn’t a basic 21-sound code. It’s a system of about 300 distinct sound combinations, with the whales adjusting rhythm and timing in real time, speeding up and slowing down the way a musician does mid-performance. A 2025 follow-up from UC Berkeley found these clicks also contain vowel patterns, something scientists had assumed only humans could produce.
Sperm whales carry the largest brain of any animal on the planet. About 9 kg. Roughly six times heavier than yours. The evolutionary analysis in the new Science paper suggests this kind of cooperative birthing goes back over 36 million years, to the common ancestor of all toothed whales. The calf was spotted a year later, swimming with its family.
