Sperm Whales Exhibit Coordinated Group Midwifery in Documented Birth Off Dominica

New scientific documentation details a significant instance of cooperative birthing assistance among sperm whales, offering critical insight into the species' complex social structure. Researchers with Project CETI captured the most detailed account of a sperm whale delivery ever recorded through extensive observation conducted off the coast of Dominica in July 2023.

The event, which spanned several hours on July 8, 2023, involved an entire social unit of eleven whales, consisting of both related and unrelated females, actively coordinating their efforts. This observation represents the first quantitative evidence of such cooperative birth assistance documented outside of the primate order. The immediate survival of newborn sperm whale calves, which are negatively buoyant and must be rapidly lifted to the water's surface for their initial breaths, necessitates collective action.

The observed group, which researchers have studied for over two decades in the region, included individuals from two distinct matrilines. The mother, identified as Rounder, received assistance that involved synchronized lifting behaviors, physical stabilization of the delivery process, and continuous rotation to guide the calf upward for several hours. Following delivery, a core group of four whales—including Rounder, her half-sister Aurora, an unrelated juvenile named Ariel, and an older relative named Atwood—maintained near-constant physical contact with the newborn for an hour.

This sustained, cooperative postnatal care involving both kin and non-kin suggests that such behavior reinforces the crucial social bonds fundamental to sperm whale society. Giovanni Petri, Project CETI’s network science lead, noted the pronounced and uncommon interaction between non-genetically related groups, suggesting it may represent an evolutionary survival response for the species. The entire birthing process, from labor through immediate post-delivery support, was managed by a coordinated, group-level response from all eleven assembled unit members.

Acoustic analysis conducted during the delivery revealed significant shifts in vocal styles, including the emergence of structures similar to human vowels. Project CETI, which employs advanced tools such as aerial drone footage, computer vision, and machine learning to interpret sperm whale communication, found that these vocalizations possess spectral patterns resembling human vowels and diphthongs, such as 'a' and 'i' sounds. These findings suggest that cooperative calf care may be an ancient evolutionary trait shared among toothed whales, potentially predating their common ancestor by more than 36 million years. The calf was later sighted alive with its family unit one year post-event, indicating a high probability of survival to adulthood. The research, published in journals including Science and Scientific Reports, establishes a quantitative framework for understanding the complex cognitive and communication abilities necessary for such intricate social behaviors.