Video: How dolphin moms reunite with their babies

Imagine if, when you wanted to get your kid’s attention, you called them—not by their name—but by your own. It turns out that bottlenose dolphin mothers do just that. They use “signature whistles,” high-pitched, individualized calls, which function like human names. Scientists have known about these whistles since the 1990s. But now for the first time, they have confirmed that moms use the whistles to call their babies home. To do so, behavioral biologists used hand and verbal signals to ask a captive bottlenose dolphin, Merina, to retrieve either a toy or her calf, Windley, from a few meters away, in a seawater lagoon. When Merina retrieved a toy, she whistled in just three of 29 trials. But when the mother dolphin went to retrieve her calf, she whistled in over 30 of 50 trials, the group reports in the May 2016 Behavioural Processes. Later spectrogram analysis confirmed they were signature whistles, produced through tissue vibrations near the blowhole. While the study is the first to confirm this link between dolphin motivation and communication, some ecologists question its validity, since the dolphins were artificially separated and the female was directed to behave a certain way. Now, if only we could ask Merina and Windley what they think!