A first look at a sperm whale’s birth reveals teamwork in supporting the newborn

The sperm whale was assisted in giving birth by 10 other females in her social unit – the first time such an event has been observed in a non-primate.

In July 2023, scientists who had been monitoring a group of sperm whales in the Caribbean since 2005 noticed that all 11 females in the group had gathered near the surface. By chance, the scientists had drones in the air and could observe and record the event.

Shortly thereafter, calf flukes began to emerge from his mother. The birth took place over the next half hour, during which the other females coordinated into a highly synchronized formation to protect the mother and newborn.

Once the baby was born, the female whales gathered around and took turns to ensure that it was raised near the surface so that it could breathe and have time for its tentacles to fully develop. In the first few hours, newborn sperm whales do not float and cannot stay afloat on their own, so such help is considered essential to prevent the calves from drowning.

“This is the first evidence of assisted birth in a non-primate,” says a member of the team Shane Gero in the CETI project in New York.

Such complex behavior was once thought to be exclusive to humans, he says, and has only recently been observed in subhuman primates.

“The sperm whale society is driven by strong female leadership, in which knowledge is shared across generations of females,” says Gero. “It’s fascinating to see the intergenerational support from a grandmother to her birth daughter and the support from other, unrelated women.”

When the short-finned pilots arrived about 18 minutes after birth, the team observed clear defensive responses from adult female sperm whales.

“They consistently placed at least one adult between the newborns and the pilots, even from below,” says a team member Giovanni Petri at Northeastern University London. “On several occasions, the adults opened their jaws and jerked their heads toward the approaching whales. In one case, the pilot rammed the nose of the adult female closest to the newborn at high speed. Sperm whales also changed direction when the pilots swam directly in front of the pod.”

The researchers deployed underwater sound recording equipment to monitor the calls of the sperm whales as part of it independent study.

“Acoustically, what we found is remarkable,” says Petri. “We found statistically significant shifts in overall vocal style at key moments: the onset of labor and first interactions with pilot whales.”

These shifts were far beyond the normal variations seen in the day-to-day socialization of the unit, he says. Once the critical moments surrounding the birth had passed, the group’s vocal style returned to baseline.

The combination of acoustics and observation allowed the researchers to “connect what these animals are doing to what they are saying,” says Petri.

Gero says the team has not yet been able to determine the gender of the calf. “We hope to see the newborn in the field in the next few months, in which case we would give it a name. But we know it has survived the critical first year of its life, in which calf mortality is very high.”

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