I have 4 Lavender Orpingtons, about 7 weeks old or so. The chicks are all healthy, but are of varying sizes. One is much larger than the rest, two are in the middle, then the other is undersized. They were moved out to the coop this last week end and have been doing well despite the heat. I keep them separate from my 14 week old BR's by some chicken wire. I am seeing that the smallest one is showing what I think are some signs of major feather pecking. Her neck is all but naked and her breast has bald spots. The two middle sized ones are feathering out, but the feathers are looking cut and ragged. One also has a bald spot on her neck. The largest is feathering out well and looks very nice, with no sign of problems. I assume this means she is the one doing the pecking. I have never seen any of the pecking, but I don't know what else it could be. I have a 3'x1.5' tractor that I can put in the coop and isolate her if that is what needs to be done. If so, how long will this need to be done? Any help with this issue will be much appreciated.