Attached is a picture of my female that has been loosing feathers. I have 2 male and three female pekin ducks. About 6 months ago, Zorro started losing feathers on the end of her wings. Recently, she started to lose more on her whole wing. The other ducks are fine and don't have any problem, but Zorro is the only one that is losing her feathers. Does anyone have any idea of what it could be?