So what's really going on here? Well, it's hard to say, but The Dodo talked to a few dolphin experts to get their theories.
Mark Palmer, Associate Director of the International Marine Mammal Project at the Earth Island Institute gave a few theories, based on the similar behavior of other marine mammals:
- They are using the wind to push their flukes and "sail" along, like right whales in Argentina have been observed doing - They could be female dolphin raising their tails out of the water to prevent males from mating with them, like gray whales are known to do - They could be trying to warm their flukes in the sun -- sea lions will often stick their flippers above the water to warm them, and then circulate the warm blood through their bodies in the cold water - They could simply being doing it to have fun Ric O'Barry, Campaign Director of the Dolphin Project, said:
I think they are simply having fun. I have seen this before. They could also be catching the wind with their tail fluke. You might notice that most of the flukes are facing the same direction - the direction of the oncoming wind.
Regina Asmutis-Silvia, Executive Director of the Whale and Dolphin Conservation, said this behavior is referred to as "sailing" and pointed to this video of Southern right whales: