Once you see something it’s hard not to see it. You ‘get your eye in’. I’ve recently seen a few different ones on various walks and I can’t resist taking photos of them. This could be a duck or a pigeon feather? I don’t know. I remember learning how feathers have thin strands with little hooks on them so when a bird preens it’s feathers the hooks can sort of zip the feathers up and hold the strands of the feathers together? I don’t know exactly how it works. I guess I should look it up on line or find a book with details in it. It is fascinating to think about the mechanics of birds wings.