Penguins Wear a Shield of Cold Air in Winter

Jennifer Viegas, Discovery News

Emperor penguins “wear” an invisible shield of cold air that helps to prevent body heat loss, allowing the flightless birds to survive the sub-zero temps of Antarctica, a new study finds.

The report, published in the journal Biology Letters, demonstrates just how hardy the birds are.

“In most birds, plumage is able to resist the flow of heat, such that surface temperature is normally a few degrees above ambient temperature,” wrote Dominic McCafferty of the University of Glasgow and his colleagues. For emperor penguins, however, “During clear sky conditions, most outer surfaces of the body were colder than surrounding sub-zero air … In these conditions, the feather surface will paradoxically gain heat by convection from surrounding air.”

Continued:  http://www.livescience.com/27677-penguins-wear-a-shield-of-cold-air-in-winter.html