My 4 month old Buff Orpington roos are having a problem. I found one today sitting on the ground being pecked and when I lifted it up all of it's tail feathers were missing and it's vent had been eaten open. I isolated it and it died in a couple of hours, as expected. Then I saw another one running around behaving normally but with a bleeding rear end. When I examined it, all of the tail feathers had been pulled out but no vent damage yet. I isolated it as well and will see how it's doing in the morning. Since I was planning on culling most of the roos at maturity anyway, only keeping two for breeding, I am not too upset, but don't want it to spread to the hens. There are several possibilities I am considering: (1) The two roos in question got into it and pulled each other's tail feathers out; (2) There was a loud scream from what I thought was just one bird yesterday when I went to close the roof on the mobile coop and there was a chicken that had flown up and perched without my noticing. Maybe there were two of them and the lid pulled their feathers out; (3) They have mites or lice; (4) The geese and/or ducks that are in with them are pulling out their tail feathers when they get rowdy; (5) There is some kind of Ebola virus thing going on. Please help me before this spreads!