STEVE INSKEEP, HOST:
Good morning. I'm Steve Inskeep. Researchers have discovered one of the ways that dolphins communicate, it's something people do, baby talk. In a new study, female bottlenose dolphins changed their tone when talking to their calves. All of the 19 moms whistled a unique signal higher and greater than their usual tone. It took more than 30 years to collect the data. Aw, look at the little baby dorsal fin.
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