Pregnant Dolphins Sing to Their Babies in the Womb

Altantic Bottlenose Dolphin and her calf swimming in sunlit water

When I was pregnant, there was all kinds of literature on how and when babies can start to hear you talking or singing or reading while in the womb. It’s supposed to help them recognize your voice, start learning before they’re even born, and to help parents bond with those babies before they can hold them in their arms.

I always felt kind of silly doing it (and with my second one I didn’t have time), but it seems that human science must be onto something – because dolphins do this for their unborn babies, too.

New research has found that dolphins use “signature whistles” to identify and communicate with one another, sort of like human beings use names, and that pregnant females begin using a unique whistle to address the baby in the months before and weeks after the birth.

The researchers, from the Marine Mammal Behavior and Cognition Lab at the University of Southern Mississippi, presented their findings at the American Psychological Association conference.


Audra Ames, the lead researcher, said,

“It’s been hypothesized that this is part of an imprinting process.

We actually do see that human babies develop a preference for their mother’s voice in the last trimester.

We don’t know if that’s something that’s going on here, but it could be something similar.”

To come to their conclusions, the team studied 80 hours of audio surrounding the birth of the calves, from captive dolphins in Vallejo, CA.

Not only did they observe mother dolphins using these unique whistles to “talk” to their babies, they also noted that other dolphins in the area were quieter during the few months before the birth.


A few weeks after birth, the mother’s repetitions tapered off and the other dolphins increased their own whistles once again.

Strange, but true – of course, there’s surely much more to learn about dolphins and their parenting, but I, for one, no longer feel silly for all those hours I spent reading books to my swollen belly.