You know instantly when someone is speaking to an infant or small child. It turns out that dolphin mothers also use a kind of high-pitched baby talk.

found that female bottlenose dolphins change their tone when addressing their calves. Researchers recorded the signature whistles of 19 mother dolphins in Florida, when accompanied by their young offspring and when swimming alone or with other adults.

The is a unique and important signal 香蕉视频直播� akin to calling out their own name.

香蕉视频直播淭hey use these whistles to keep track of each other. They香蕉视频直播檙e periodically saying, 香蕉视频直播業香蕉视频直播檓 here, I香蕉视频直播檓 here香蕉视频直播�,香蕉视频直播� said study co-author Laela Sayigh, a Woods Hole Oceanographic Institution marine biologist in Massachusetts.

When directing the signal to their calves, the mother香蕉视频直播檚 whistle pitch is higher and her pitch range is greater than usual, according to the study published in the journal,

香蕉视频直播淭hat was true for every one of the moms in the study, all 19 of them,香蕉视频直播� said biologist Peter Tyack, a study co-author from the University of St. Andrews in Scotland.

Obtaining this data was no simple feat. Over more than three decades, scientists placed special microphones multiple times on the same wild dolphin mothers in Florida香蕉视频直播檚 Sarasota Bay to record their signature whistles. That included years when they had calves and when they didn香蕉视频直播檛 香蕉视频直播� dolphin calves stay with their mothers for an average of three years in Sarasota, and sometimes longer. Fathers don香蕉视频直播檛 play a prolonged role in parenting.

香蕉视频直播淭his is unprecedented, absolutely fantastic data,香蕉视频直播� said Mauricio Cantor, an Oregon State University marine biologist who was not involved in the study. 香蕉视频直播淭his study is the result of so much research effort.香蕉视频直播�

Why people, dolphins or other creatures use baby talk isn香蕉视频直播檛 certain, but scientists believe it may help offspring learn to pronounce novel sounds. Research dating back to the 1980s suggests that human infants may to speech with a greater pitch range. may alter their calls to attract and hold offspring香蕉视频直播檚 attention. And Zebra finches and slow down their songs to address chicks, perhaps making it easier to learn birdsong.

For the dolphin study, the researchers focused solely on the signature call, so they don香蕉视频直播檛 know if dolphins also use baby talk for other exchanges 香蕉视频直播� or whether it helps their offspring learn to 香蕉视频直播渢alk香蕉视频直播� as it seems to do with humans.

香蕉视频直播淚t would make sense if there are similar adaptations in bottlenose dolphins 香蕉视频直播� a long lived, highly acoustic species,香蕉视频直播� where calves must learn to vocalize many sounds to communicate, said Frants Jensen, a behavioral ecologist at Denmark香蕉视频直播檚 Aarhus University and a study co-author.

Another possible reason for using specific pitches is to catch the kids香蕉视频直播� attention.

香蕉视频直播淚t香蕉视频直播檚 really important for a calf to know 香蕉视频直播極h, Mom is talking to me now香蕉视频直播� __ versus just announcing her presence to someone else,香蕉视频直播� added Janet Mann, a marine biologist at Georgetown University, who was not involved in the study.

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Follow Christina Larson on Twitter at: @larsonchristina

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute香蕉视频直播檚 Science and Educational Media Group. The AP is solely responsible for all content.

Christina Larson, The Associated Press

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