WASHINGTON (AP) – You know instantly when someone is talking to a baby or toddler. It turns out that mother dolphins also use a kind of high-pitched baby talk.
A study published on Monday found that female bottlenose dolphins change their pitch when addressing their young. The researchers recorded the characteristic whistles of 19 mother dolphins in Florida, when they were accompanied by their young offspring and when swimming alone or with other adults.
The dolphins’ signature whistle is a unique and important signal, similar to calling their own name.
“They use these whistles to follow each other. They periodically say, “I’m here, I’m here,” said study co-author Laela Sayigh, a marine biologist at the Woods Hole Oceanographic Institution in Massachusetts.
According to the study published in the journal Proceedings of the National Academy of Sciences, when she directs the signal to her calves, the tone of the mother’s whistle is higher and its range is greater than usual.
“This was true for every mother in the study, all 19,” said biologist Peter Tyack, co-author of the study at the University of St. Andrews in Scotland.
Obtaining this data was not easy. For more than three decades, scientists repeatedly placed special microphones on the same wild dolphin mothers in Florida’s Sarasota Bay to record their signature whistles. This included years when they had calves and when they didn’t – dolphin calves stay with their mothers for an average of three years in Sarasota, and sometimes longer. Fathers do not play an extended role in parenthood.
“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.”
It’s unclear why people, dolphins or other creatures use baby talk, but scientists believe it can help offspring learn to pronounce new sounds. Research dating back to the 1980s suggests that human infants may pay more attention to speech with a greater range of pitches. Female rhesus monkeys can modify their calls to attract and hold the attention of their offspring. And zebra finches raise their pitch and slow their songs to address the chicks, perhaps making it easier to learn the birdsong.
For the dolphin study, the researchers focused only on signature call, so they don’t know if dolphins also use baby talk for other exchanges – or if it helps their offspring learn to talk. “talk” as it seems to do with humans.
“It would make sense if there were similar adaptations in bottlenose dolphins – a long-lived, highly acoustic species,” where calves must learn to vocalize many sounds to communicate, said behavioral ecologist Frants Jensen. at the Danish University of Aarhus and co-author of a study. author.
Another possible reason for using specific locations is to attract children’s attention.
“It’s really important for a calf to know, ‘Oh, mommy is talking to me now,’ rather than just announcing its presence to someone else,” added Janet Mann, a marine biologist at Georgetown University, who did not participate in the study.
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