Dolphins Mimic Loved Ones' Whistles to Reunite

A new study finds that dolphins mimic the whistles of their loved ones to trigger a reunion.

Dolphins are social animals that live in groups called pods. Each dolphin develops a signature whistle that describes its individual identity. Previous studies have shown that dolphins copy the distinct whistles of one another. But it was not clear whether the signal was an aggressive one or a friendly signal.

A team of Scottish and American scientists studied the recordings of signature (unique) whistles of wild and captive bottlenose dolphins to find out which marine animal copied one another's whistle. They found copying present in mothers and their offspring as well as adult males, who copied whistles of those dolphins with which they had strong social bonds.

"Interestingly, signature whistle copying was only found in pairs of animals composed of mothers and their calves or adult males who form long-term alliances with one another," Dr. Stephanie King, from University of St. Andrews, U.K., said in a statement.

King and her colleagues suggest that dolphins mimic the whistles of those they are close to and want to see again.

The research team also found slight alterations in the whistles that the dolphins imitate. The marine animals make small changes to the copies so as to avoid confusion to the listeners. Immediately after the owner of the whistle calls first, animals that are closely associated to the owner will mimic when they want to reunite with that specific individual. This behavior is called as vocal matching.

"Our next step is to use sound playbacks to see how dolphins respond to being matched with a copy of their own signature whistle. If they react we would know that copying of signature whistles can be used to address dolphins," Dr. King said.

The findings of the study are published this week in the journal Proceedings of the Royal Society B.