This psychedelic image of Emperor penguins is not a fancy blacklight poster (although it would make a good one), but a thermal image taken to help find out how penguins stay warm in the Antarctic. THe surprising find was that while the birds generated heat inside like all warm-blooded animals, a large part of the penguins' outer feathers were actually colder than the surrounding air! How can this adaptation possibly help them?
The penguins do lose internal body heat to the surrounding air through thermal radiation, just as our bodies do on a cold day. Because their bodies (but not surface plumage) are warmer than the surrounding air, heat gradually radiates outward over time, moving from a warmer material to a colder one. To maintain body temperature while losing heat, penguins, like all warm-blooded animals, rely on the metabolism of food.
The penguins, though, have an additional strategy. Since their outer plumage is even colder than the air, the simulation showed that they might gain back a little of this heat through thermal convection—the transfer of heat via the movement of a fluid (in this case, the air). As the cold Antarctic air cycles around their bodies, slightly warmer air comes into contact with the plumage and donates minute amounts of heat back to the penguins, then cycles away at a slightly colder temperature.
Most of this heat, the researchers note, probably doesn’t make it all the way through the plumage and back to the penguins’ bodies, but it could make a slight difference. At the very least, the method by which a penguin’s plumage wicks heat from the bitterly cold air that surrounds it helps to cancel out some of the heat that’s radiating from its interior.
When you're trying to get through the winter at the bottom of the world, every little bit counts. Read more about the research at Smithsonian's Surprising Science blog. Link
(Image credit: © Université de Strasbourg and Centre National de la Recherche Scientifique (CNRS), Strasbourg, France)