A suggestion by Bangor University Professor Roger Hughes of the School of Biological Sciences, that bubble trails seen in footage of emperor penguins swimming to the sea surface are produced to reduce drag is published in the November 2012 edition of National Geographic. The intriguing hypothesis about how penguins exit the water that occured to Prof Hughes while watching TV, originally led to a research paper revealing just how the penguins could manage this. Collaborators at University College Cork and the Technical University of Denmark showed that ‘lubrication’ provided by tiny air bubbles released from under the feathers could allow penguins to gain enough speed to leap out of the water and onto the ice shelf.
Prof Hughes said: “I was watching the Blue Planet series and saw that emperor penguins always produce a bubble trail as they ascend to leap out of the water. The bubbles look like the con-trails of aircraft –a point also noticed by the entertainment industry in the cartoon film, ‘Happy Feet’ where penguins perform ‘formation–swimming’ with synchronized bubble trails! My wife had been talking to me about ‘shark-skin’ swim suits with a texture that reduces drag and I wondered if a coating of bubbles would have the same effect in penguins.
The full paper title: Drag reduction by air release promotes fast ascent in jumping emperor penguins—a novel hypothesis.
is published in : Marine Ecology Progress Series Vol. 430: 171–182, 2011