Why do spinner dolphins spin?
True athletes of the sea, spinner dolphins are famed for doing just that – leaping out of the water in spectacular 3m aerial corkscrews. To perform the pirouette, an individual accelerates through the water with rapid pumps of the tail, then uses its muscle power to drive a tight twist as it breaks the surface.
Underwater, a spinner can generate one to two rotations per second, but out in the open air it can perform up to seven. The display usually ends with a resounding bellyflop.
Theories abound as to why spinners spin. The behaviour could convey a state such as happiness, anger or fear; it may be a display of dominance or courtship; it could be play, or a means of detaching parasites and remoras. The splash of the bellyflop may be a method of communication, informing others near and far of an individual’s position in the water.
Spinning is apparently contagious – once one dolphin gets going, others join in.