Originally Posted by rollingthunder
Could be - seen loads yesterday not a feather moulting or missing on any of them.
I am not a moult expert but afaik raptors moult individual flight feathers so that they are able to feed and function whilst doing so unlike waterfowl that eclipse and warblers that have pre and post migration moult. To actively have a moult regime as suggested would almost lead to the bird having difficulty to either moult or migrate...
Looking again at the feathers a parasite snipping off barbs looks like a real possibility - those secondaries look defoliated, not twisted.