Just some info to pass along... My M2 female started her seasonal feather biting despite the bathing. This year I turned on a full spectrum flurescent bulb and the biting stopped almost instantly!!! I am in Md, USA where right now the sun doesn't get much above 30 degrees and there is only about 10 hrs of daylight. Even with plenty of windows, I was told that glass still filters too much of the UV.
Now on another note, I was discussing autism with a friend of mine and the similarities between a frustrated plucking bird and an austic child came up (both locked in a world where they can't interact with others in a healthy way) and I got to wondering if full spectrum lighting would help these children. I worked with one once. He use to beat his face all day. One day I took him outside and let run around till he was exhausted...he laughed his heart out. Could help be so simple?