emperor penguins, like other birds, have the capacity to fluff their feathers and insulate their bodies with a layer of air. but where most birds have rows of feathers with bare skin between them, emperors have a dense, uniform coat of feathers with tiny filaments at the base which allows them to release this layer of air as lubricating microbubbles. in doing so, the penguins are able to reduce their drag and the viscosity of the water, thus enabling them to swim faster. photos by paul nicklen (previously featured)
