Bottlenose dolphins use baby talk with their little ones

Scientists recorded the sounds of mother dolphins for 30 years to observe this conclusion.
Loukia Papadopoulos
A dolphin and her baby.jpg
A dolphin and her baby.


Previous studies have indicated that dolphins are advanced sentient beings that partake in many activities undertaken by humans. Now, we can add one more to the list: baby talk.

A study published on Monday and reported Tuesday by The Guardian found that female bottlenose dolphins coo their calves, using a kind of high-pitched baby talk. To come to this conclusion, researchers recorded the sounds of 19 mother dolphins in Florida, both when accompanied by their babies and when swimming alone or with other adults.

"Our data provide an example of convergent evolution of motherese in a nonhuman mammal and support the hypothesis that motherese can facilitate vocal learning and bonding in nonhumans as well as humans," the researchers wrote.

They further compared the noise to a sound akin to calling out their own name.

“They use these whistles to keep track of each other. They’re periodically saying, ‘I’m here, I’m here’,” told The Guardian study co-author Laela Sayigh, a Woods Hole Oceanographic Institution marine biologist in Massachusetts.

The scientists noted that signals directed to calves boast a whistle pitch that is higher and exhibits a range that is greater than usual.

“That was true for every one of the mums in the study, all 19 of them,” said biologist Peter Tyack, a study co-author from the University of St Andrews in Scotland.

A revolutionary study

The study took three decades to complete but has been hailed as revolutionary.

“This is unprecedented, absolutely fantastic data,” said Mauricio Cantor, an Oregon State University marine biologist who was not involved in the study. “This study is the result of so much research effort.”

However, since the researchers focused solely on the signature call, it remains unclear whether dolphins also use baby talk for other exchanges and whether it helps their infants learn to “talk” as it seems to do with humans.

“It would make sense if there are similar adaptations in bottlenose dolphins – a long lived, highly acoustic species,” where calves must learn to vocalize many sounds to communicate, said Frants Jensen, a behavioral ecologist at Denmark’s Aarhus University and a study co-author.

Researchers have suggested that the change in tone used during baby talk could be to catch the kids’ attention.

“It’s really important for a calf to know ‘Oh, Mum is talking to me now’ – versus just announcing her presence to someone else,” told The Guardian Janet Mann, a marine biologist at Georgetown University, who was not involved in the study.

The study was published in the journal Proceedings of the National Academy of Sciences.