In July 2023, researchers in the Caribbean tracking a sperm whale found an unusually still group of eleven animals near the surface. Marine biologist Shane Gero and his team launched two aerial drones and, as activity suddenly increased and blood appeared in the water, captured what turned out to be a sperm whale giving birth.
The drone footage recorded the labor and the moment the calf’s fluke emerged — sperm whales are born tail-first — while submerged microphones picked up clicks and calls. Project CETI combined the visual and acoustic recordings with machine learning and many years of field observation to identify the mother, nicknamed Rounder. The event and its analysis are reported in papers in Science and Scientific Reports and represent the most detailed documentation of a sperm whale birth to date.
Sperm whales live in matrilineal groups made up of grandmothers, mothers and daughters; males typically depart in their mid-teens. Rounder’s Unit A contained two matrilines that do not usually spend much time together, and about half the whales present were not close kin. Despite that mix, the videos show several individuals — including non-relatives — taking turns keeping the newborn afloat during its first three hours.
Newborn sperm whales are negatively buoyant because they lack the fully developed oil-filled nasal sac adults use to rise at the surface. Left alone, calves can sink. The recorded behavior shows a coordinated effort: whales supported the mother, cradled and repeatedly lifted the calf to the surface so it could breathe. Gero and colleagues interpret this as evidence of a complex cooperative society in which help is not explained solely by close kinship, implying expectations of mutual aid among group members.
Philippa Brakes, a behavioral ecologist at the University of Exeter who was not involved in the studies, said the findings suggest layers of cultural and innate behavior, comparing the scene to people setting aside differences to assist someone in urgent need.
Gero and his team are continuing to analyze the recordings to better understand the social dynamics at play and to answer remaining questions. He also highlighted a broader takeaway: overcoming big challenges often relies on working together across differences — a message many humans may find timely.