In our main coop we have one rooster - a Barred Rock. In the same coop/run we have 6 Barred Rock hens and 6 Buff Orpington hens. As best we can tell, the rooster only mates with the Barred Rock girls, not the Buffs. Is this normal? Is it likely that the rooster is sticking with his own breed? I assumed that he wouldn't be very picky about the hens. Or maybe it's just coincidence that we never see him with a Buff? I should mention that all of the chickens have just turned 6 months-old. Silly, I know, but my husband, daughter and I are curious!