I have had my aviary for Three years now and this winter we decided to do something a little different. Instead of using sheets for wind block we used tarps with only the front door as the opening. I don't know if the lack of fresh air along with a red heat light instead of a black one has done something but for about a week my doves have bee looking like their head feathers were ruffled up. Today when I went in to feed them I got a close look at them and their skin was really weird and peeling around their mouths... So when I inspected it huge pieces of feather and skin came off! There was no blood or meat underneath it, just naked skin. One two of them they had weird patches on their wings as well. Where it is the feathers come out with light pressure and it is just gross. I haven't introduced any new birds in since October and I just don't know what is going on. Tomorrow I am cleaning out the bottom but we have never seen anything like this before.