My girls won't be a year old til April so I assume the roo is making their feathers right b4 their tail feathers look flattened. That's y I originally thought of separating them. Ladies were so calm last time and i don't have to keep my eye on roo while in the coop. Still, the clumps of feathers i find are under the roost or in the nest box where not much mating goes on so i thought vermin may be pulling feathers. Reread about 1st molt and that may be it. Been raining here so haven't put door on for Mr. Peck yet.