The numbers in the literature related to the penguins’ contour feathers -- the stiff, shapely plumes that resemble those used in quill pens. The contour feathers encase the body and the ...

This is a closeup of a back contour feather barb from a male eastern bluebird; demonstrates a protein with channel-type nanostructure. (Scale bar = 500 nanometers.) Image courtesy of Richard Prum ...