Scientists recorded a sperm whale birth up close for the first time. They discovered something extraordinary. 

Across the half century or so that seafarers and scientists have spent studying the habits of sperm whales, some of the most elemental parts of these creatures’ lives have eluded human observation. That includes their births. The world’s oceans are vast in breadth and depth, and sperm whales frequent their furthest reaches. For decades, there was just one published scientific report of a sperm whale birth, observed after the fact and from a distance. 

But now the long-unseen full picture of a sperm whale birth is coming into view, offering remarkable new insights into how these whales communicate and cooperate.   

In July 2023, Shane Gero, a whale biologist and scientist in residence at Ottawa’s Carleton University, was on a sailboat off the coast of Dominica when he and his colleagues stumbled upon a whale in labor. Gero is a National Geographic Explorer and the Biology Lead of Project CETI, a scientific initiative to decipher sperm whale communication. That day in the Caribbean, he and his team were equipped with cameras and hydrophones to capture the fortuitous moment. “All the biologists on the boat were losing their minds,” said Gero.  

The event they recorded, described in a pair of scientific studies published today, gives an exceptionally detailed picture of a sperm whale family’s collaborative effort to care for a mother and infant—and provides the first quantifiable evidence of an animal species other than primates assisting during the birth process. For a human family, a birth is a moment of great social and emotional significance. The portrait of this sperm whale birth seems to show something no less meaningful. 

On that July morning, Gero and the team were observing a group of whales they know well called Unit A. Sperm whales live in families made up of adult females and calves. Unit A contains two distinct genetic lines—one descending from a matriarch named Lady Oracle  and another descending from a matriarch called Fruit Salad.    

Looking into the water, Gero noticed that the whales were acting strangely. Normally the 11 members of Unit A would be spaced out to forage, but on this morning they were grouped together, all facing a female named Rounder. The scientists watched as Rounder released a dark gush of blood. When she started to push out the furled tip of a small tail, they realized they were witnessing something extraordinary.  

Over the next five and a half hours, during the birth and its aftermath, Gero and the Project CETI team used a hydrophone and two aerial drones to record the activity of all 11 members of Unit A. The data would offer an unprecedented view of a critical event, the analysis of which marks the latest breakthrough from Project CETI, whose research has already transformed our understanding of how sperm whales live and communicate with each other. Ultimately, the team hopes its work will encourage a broader movement to protect the species. 

For a mammal, giving birth underwater is a dangerous enterprise. Sperm whale calves are born tail first, lest they drown coming out. For the first hour or so of their lives, newborns cannot swim, so they must be lifted to the surface to take their first breaths. As soon as Rounder gave birth, the family members in Unit A clustered together to collectively raise the calf up to the surface so the young whale could breathe. For the next three hours, they traded off supporting the infant. They also kept other animals—a pod of curious pilot whales and a large group of Fraser’s dolphins—at bay during the birth. Pilot whales can be aggressive toward sperm whales, and the adults in Unit A maneuvered to shield the newborn from the interlopers until they left. Eventually, as the afternoon went on, the members of Unit A drifted away to resume foraging, leaving mother and calf together.  

Later, to untangle the roles that each whale played before, during, and after the birth, Project CETI fed drone footage of the event into a machine learning program. The model analyzed and identified patterns within a range of data, including the orientation of the whales’ bodies in the water, how often each whale interacted with each of the other whales, and how coordinated their movements were. While the software was able to separate the movements of individual animals from images of 11 whales thrashing and splashing in the water together, the task of identifying which whales were Rounder, Lady Oracle, or Fruit Salad required hand annotations from Gero. “We needed a village of scientists to be able to make sense out of this event,” said David Gruber, founder and president of Project CETI and a National Geographic Explorer.  

The team’s analysis of the extensive video data, published today in the journal Science, reveals a surprisingly intricate set of interactions. Project CETI’s network analysis team, led by mathematician Giovanni Petri, was able to track how often whales that were not genetically related to the calf participated in protecting it and Rounder. (Quite often, it turns out.) Measuring the orientation of the whales helped the researchers identify a shift of the group’s attention from the mother to the newborn calf after delivery, which suggests an ability to address immediate needs as they arise.   

Additionally, the team discovered that the whales’ social positions within the group may have dictated their roles in the birth and post-birth care. Normally, when male sperm whales reach adulthood, they leave their families and venture out into the ocean as solitary nomads. Allan, a juvenile male and the calf’s uncle, had been spending time alone in the months before the birth. This day, he stayed with the group and even tried to approach the calf after the birth—but the group’s older females squeezed him out and relegated him to the outskirts of the circle. The most closely related female whales to Rounder stayed nearest to her and her calf.  

During the birth’s most eventful moments, researchers noticed that the sperm whales changed their vocalizations, which resemble patterns of clicks. At the time of the birth, and during the pilot whales’ approach, the sperm whales both clicked more frequently and changed the style of their clicks—a response not unlike the collective noise of a group reacting to something exciting going on in front of them.   

The most frequent vocalization Unit A made was the 1+1+3 coda, which consists of two clicks followed by three sharp clicks in rapid succession: click-click-clickclickclick. Researchers believe the call to be an identity marker of the whale clan they belong to and suspect it reinforces social belonging.

In order for animals to work together in this way, with a common goal in mind, Gero notes that they must have very advanced cognitive and communication abilities. “Their brain is doing a lot more work than just ‘you’re my brother,’ or ‘you smell like me,’ or ‘you spend a lot of time with me,’ ” he said. The team’s analysis of the calls, highlighted in a Scientific Reports study, indicates that communication may build strong and trusting relationships between group members that enable cooperative behavior.  

While mothers of other whale species have been observed lifting their infants to the surface, only toothed whales, a classification to which sperm whales belong, have been seen doing this as a group. The behavior, the study suggests, may be ancient and even date back some 36 million years, to the emergence of the first toothed whales.  

Almost all the whales in Unit A took turns supporting the calf directly after the delivery, signaling an intentional, coordinated effort to ensure the calf stayed aloft. Still, some bore the lion’s share of the work. A core group of whales kept closest to the calf the whole time, including its mother, Rounder, its aunt, Aurora, and its grandmother, Lady Oracle. Curiously, a juvenile named Ariel who was not related to the calf also stayed close—perhaps, the paper speculates, to practice mothering skills. 

From an evolutionary perspective, it makes sense for animals to help the young of their own genetic line survive. In the case of Unit A, with both kin and nonkin assisting at birth, the incentives are more complex. Gero said that though it has long been thought  the cooperative care of calves might act as a social currency that contributes to sperm whales’ collective societies, measurable evidence of these relationships was hard to get. This joint effort, Gero said, “speaks to the strength of that social contract between Fruit Salad’s family and Lady Oracle’s family.”  

For humans, nonkin helping out in a birth is standard practice. While it was once thought to be among the social behaviors unique to humans, recent research on bonobos and other primates has revealed evidence to the contrary. Ethnologist Elisa Demuru observed female bonobos stretching their hands out under the birthing mother as if to catch the baby, waving away flies, chasing away males, and huddling around the mother as a protective shield. “In this moment in which one female is very vulnerable, they are there to help,” said Demuru, who reported the findings in a 2018 study in Evolution and Human Behavior. Bonobos, she noted, live in female-dominated, strongly bonded social groups. This is also true of sperm whales. 

The importance of these animals’ social networks, Gruber explained, “opens up even more questions about how deep and complex their worlds are.” The next step for Project CETI is to match the audio they captured to their visual data of the whales so that the scientists can link the whales’ codas to what they were doing at the time. That will bring CETI closer to comprehending what the codas might mean. “The ultimate goal,” Gero said, “is to understand the things that matter to beings who are fundamentally different from us." 

As for the calf, it was spotted a year later, alive and well, its birth a day no more remarkable than any other.