When feeding, aquatic birds known as phalaropes often spin rapidly on the water' s surface, pecking for food during each revolution  To execute these spins, phalaropes kick one leg harder than the other  This action creates upwelling currents
Because plankton on which phalaropes feed typically occurs in greater quantities well below the surface, it is hypothesized that by spinning phalaropes gain access to food that would otherwise be beyond their reach
Phalaropes do not usually spin when food is abundant at the surface.