Thirty long years of both citizen scientists and active researchers observing dolphins in the wild has revealed something rather neat: they can teach each other how to “walk” on their tail atop the ocean waves.

It’s been thoroughly documented before that humans can successfully teach dolphins such tricks in captivity, but this new study – to be published in The Royal Society: Biology Letters in the near-future – clearly describes its occurrence in open waters, which means more than you think it might.

The research, led by Whale and Dolphin Conservation (WDC), as well as the Universities of St. Andrews and Exeter, noted that tail walking isn’t exactly a common sight, but plenty of bottlenose dolphins (Tursiops aduncus) in the waters of Australia’s Adelaide engage in the sick dance move. So where did it come from?

Billie the dolphin was rescued from a polluted creek back in 1988. She spent several weeks in a dolphinarium there before being released back into the wild. She then began tail walking, something she would have seen performing dolphins do while in containment.

Importantly, other wild dolphins that have never put one single flipper in such an artificial environment in their lives also began tail walking. This is presumably because they watched Billie do it and fancied giving it a go themselves.

The WDC have observed wild dolphins in the area performing this trick for some time now; this news report dating back to 2009, for example, describes tail walking being observed in two adult female dolphins, including Billie. It’s noted then that it appears to have no practical function and the dolphins appear to be doing it just for fun.

This is the real takeaway message here: Dolphins aren't just able to copy tricks from each other, it also appears to have a social function of some kind.