”As infants, bottlenose dolphins develop their own signature whistles to use throughout their lifetimes. Group members repeat these whistles back during vocal interactions, and we believe that the whistles form a system similar to that of human names.”
The researchers played synthetic whistles to dolphins through an underwater speaker. In 9 out of 14 cases, the dolphin would turn more often toward the speaker if it heard a whistle resembling that of a close relative, demonstrating that the synthetic signature whistle contains information that is used by the listeners to identify the caller.
Cool, huh? And in other news I read that Big Ted from PlaySchool recently texted some friends (on a cardboard mobile phone) to invite them over for a tea party. I think they still sang I'm a little teapot in analogue rather than downloading an mp3.