Researchers have discovered how the emperor penguin withstands the cold temperatures of Antarctica. The secret is  in their down, and a specific type of feather called the plumule. The plumule, one of four types of feathers on a penguin, has previously been overlooked as an important part of the insulation.

Studying three emperor penguins, researchers found these feathers form a dense mat beneath the feathers responsible for waterproofing. They also found plumules were four times denser than the other body feathers.

Original research paper published in Proceedings of the Royal Society B: Biological Sciences on October 20, 2015.

Names and affiliations of selected author

Dr Cassondra Williams, Department of Ecology and Evolutionary Biology, University of California Irvine, California, U.S.A.