Senior Producer: John Kessler Content Director: Allison Wilson Producer: Mark Bramhill Managing Producer: Conor Gearin Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. It’s a practical application of a beautiful mystery. Scientists realized that they could estimate an owl’s age based on the pattern of luminescent color on the wings, which changes predictably as birds grow and replace their feathers. The luminous owl wings do have a specific use for biologists, though. But for other birds, such as owls, we still don’t have a good idea for the reason behind the glow. Over 50 species of parrots, as well as some toucans, have similar gleaming ornaments.
For example, parakeets called budgerigars have glowing feathers on their crowns and cheeks that may help them stand out to mates. Some cases of luminous feathers have an apparent purpose. While some bird feathers simply reflect UV light, photoluminescence involves special pigments or structures in the feathers that absorb UV and then release light of their own, often in a different color. Producing this other-worldy light is a trait called photoluminescence. It’s invisible to humans without the help of an ultraviolet blacklight, which reveals a bright magenta color.
When a Northern Saw-whet Owl spreads its wings, many birds can see something our human eyes can’t: the owl’s flight feathers glow. BirdNote® Glowing Feathers Written by Conor Gearin
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