I have 3 ducks: one Pekin (male), one Kahki (female) and one female offspring of the other 2. The "daughter" has had - with varying intensity - bare quills on her wings for months. In the spring I thought it was overmating/aggression/stress from the male, then I thought maybe a misfire on molting. But here we are with a relatively calm male, molting done, and her wings look worse than ever. Thought about self-plucking but have never seen her feathers more than the others. They all free-range (within our semi-woodsy fenced yard), and I feed them chicken/cat food and fresh greens daily. The other two ducks are fully feathered and gorgeous. She looks healthy otherwise, eats great, and lays an egg nearly every day. The only other thing I can think to mention is that her feathers have always seemed much oilier than the other two ducks. Any ideas?