Owl imprint

A woman in Kendal, Cumbria, U.K., found the imprint of an owl - complete with eyes, beak and feathers - on her window (1st image). The smudge was so detailed that the Royal Society for the Protection of Birds (RSPB) identified the bird as a tawny owl (2nd image) based on its size and shape. "We don't very often see an imprint of a bird that's flown into a window that's this clear and where it's pretty obvious exactly what kind of bird it is," said the head of the wildlife inquiries team. Since the bird wasn't found, the homeowners and experts assume it flew off without serious injury. This visual evidence of a bird's impact with glass is not as uncommon as you'd think. To see more photos, check out the set of 266 Bird Imprints on Glass on Flickr (notably those tentatively identified as a dove, magpie, duck, pigeon, and another owl). The ghostly images are formed by the disintegration of powder down, the underplumage of birds including owls and waterfowl. Distinct from contour feathers because they are not "zipped together," down feathers insulate against the cold, cover the chicks of some species, and are plucked by adults to line their nests and keep their eggs warm. Rather than being molted like other feathers, powder down grows continuously, with the tips disintegrating into a powdery substance. Ornithologists believe that another function of the powder - which sometimes leaves such a striking (no pun intended) silhouette - serves to soak up water, blood, and other fluids, providing protection and facilitating preening.