What Causes White Feathers on Birds That Are Normally Colorful?
When birds suffer serious injuries, sometimes replacement feathers grow in pure white. These injuries could include such things as: • losing feathers after narrowly escaping from a hawk or cat; • bonking repeatedly into a window; or, • recovering from a horrible case of lice or mites. What else can cause white feathers? Some birds seem to grow more and more white feathers as they age. Robins often grow more white feathers on their faces and throats as they get older. But not all partial albinos get their peculiar and interesting color patterns from trauma or age. In some birds this seems to be a genetic condition, with patches of skin on both sides lacking pigment from early in life. These partial albinos seem to show perfect symmetry in their white patches. And some birds lack a particular pigment, but not others. Journey North’s science writer Laura Erickson has seen Red-winged Blackbirds that could not produce red pigments but did produce black: they had pure white patches in their
