Mama Dolphins Sing Their Name to Babies in the Womb

By Stephanie Pappas, Live Science Contributor | August 9, 2016 08:12am ET

DENVER — Humans aren't the only species whose members speak to their babies in the womb. Dolphin mamas appear to sing their own name to their unborn calves.

New research suggests that dolphin mothers teach their babies a "signature whistle" right before birth and in the two weeks after. Signature whistles are sounds that are made by individual dolphins, which the animals use to identify one another. Calves eventually develop their own signature whistle, but in the first few weeks of life, mothers seem focused on teaching their offspring their signature sound, the scientists said.

"It's been hypothesized that this is part of an imprinting process," Audra Ames, a doctoral student at the University of Southern Mississippi, said here on Friday (Aug. 5) at the annual meeting of the American Psychological Association. [Deep Divers: A Dolphin Gallery]

Dolphin chatter

Earlier studies had shown that mother dolphins start whistling their signature whistle much more in the days before birth, and then in the calf's first two weeks of life, Ames told Live Science. There are multiple theories about why, including that perhaps moms are trying to get babies to develop their own signature sound.

But no one had studied signature-whistle rates not only before and after birth, but also in the same dolphin mother, Ames said. She and her colleagues had the opportunity to do that in late 2012 and early 2014, when a baby dolphin named Mira was born to a 9-year-old mother at Six Flags Discovery Kingdom in Vallejo, California.

The researchers captured a total of 80 hours of recordings from the two months before and the two months after the dolphin's birth. They recorded the mom and the calf as well as the five dolphins housed with them. It was important to capture the noises of the mother's peers to understand whether the communication was exclusive to the mother-baby pair, Ames said.

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