Make Eating A Challenge
Parrots spend a lot of their day foraging for food. Don't just fill their bowl and expect them to be content all day... make finding food an adventure! One way is to cover their bowl with paper. You may want to slit some "windows" in the paper until they learn to explore. Secure the paper either by tucking it in the holder, tying it with a shoelace, or using a piece of cotton string or leather strip.
My fluffy grey, Buster, loves millet. I wrap a piece of millet in a small paper bag to make it a longer and more rewarding project. He loves to tear into his bag wraps to find out what is inside.
Preparing these foraging challenges takes a little longer but I am hopeful that they will make a difference in Buster's feather issues.