I have a Wyandotte rooster with 12 hens. There were 15 hens but three have died in the last few months, and now it seems another one is dying. I'm starting to wonder if it's due to over mating. The ones that have died were all Orpingtons, and so is the one that's now dying. They were only about two years old, and died one died quite unexpectedly and quickly, the others just went down all of a sudden and then were gone in a few days. The reason I'm wondering if it might be related to over mating is because the rooster seems to have a preference for the Orpingtons. They're the only ones I ever see him mating with, and they were the ones with some loss of feathers on their backs, one quite bad. If he's selectively mating only with the Orpingtons (of which there were 6, and now there will be only 2 left), are they possibly getting injured internally? I don't see evidence of external injury. Just trying to find out if there might be a connection. He has enough hens, but seems to prefer the Orpingtons, and I'm losing them for some reason. Any thoughts?