New Recording of Sperm Whale Birth Shows Caregiving Takes a Pod

A team of researchers including Museum scientists published today the most comprehensive documentation of a sperm whale birth ever recorded.

The two studies document an entire sperm whale unit—which includes related and unrelated whales from two lines of grandmothers, mothers, sisters, and daughters—working together to support the labor, birth, and early moments of a newborn calf through coordinated lifting, physical support, and caregiving behaviors. Published in the journals Science and Scientific Reports, the research is the most detailed recording of cooperative birth assistance among non-primates.

The studies are led by scientists at Project CETI (Cetacean Translation Initiative) and are based on more than six hours of underwater audio and aerial drone footage captured in July 2023 in the waters off Dominica. Researchers have been studying the lives of sperm whale families in that area for more than 20 years.

“These findings fundamentally reshape how we understand whale society,” said Museum Research Associate David Gruber, who is a National Geographic Explorer, the founder and president of Project CETI and a professor at the City University of New York. “What we’re seeing is deeply coordinated social care during one of the most vulnerable moments of life.”

Observations of wild whale births are rare and have been recorded in less than 10 percent of whale species. The Science paper details how female sperm whales from two unrelated matrilines come together during a birth to assist the laboring mother, and both related and non-related whales take turns assisting the newborn.

The Scientific Reports paper presents a moment-by-moment account of the birth, contextualized within what is known about whale behavior, communication, and evolution. Sperm whale families are part of culturally distinct clans that communicate in dialects of click patterns. Audio data revealed distinct shifts in vocal styles during key moments of the birth, including the presence of vowel-like structures.

Sperm whale families are part of culturally distinct clans that communicate in dialects of click patterns. Three of six known members of one family unit, named Aurora, Atwood, and Accra, are shown here near the Caribbean island of Dominica.
Brian J.Skerry/National Geographic

Together, the studies suggest that cooperative caregiving during birth is an ancient evolutionary behavior.  In addition to sperm whales, the collaborative lifting of newborn whales has been observed in several distantly related toothed whale groups, so this behavior may predate the most recent common ancestor of living toothed whales, about 34 million years ago.

The behaviors documented in the studies suggest that cooperation during births reinforces social bonds between sperm whales, which underpin their large-scale society.

Female sperm whales holding the newborn sperm whale calf above water until it is able to swim on its own.
© Project CETI

“In highly social species, such as many primates—including humans—and whales, reciprocal benefits might be expected when there is long-term cooperation among individuals,” said Museum Senior Research Scientist John Gatesy, one of the co-authors on the Scientific Reports study. “For sperm whales in a group, helping protect an infant at birth may be little price to pay for help in return when you give birth in the future, or if simply being part of a group generally increases your chances of survival.”