Thank you so much. It makes sense. I'll give it a try!I believe you had said you hatched a group with all roux females right? I would breed one of those roux hens to the male you suspect is a carrier, if he is a carrier, you should get some roux males. Males will only fully show roux if they have 2 copies, if they’re a carrier, you’ll see it sometimes when he’s young around the head and neck in particular, and if compared side by side, a roux carrier rosetta will look much more red than a rosetta that came from range and wild. So you can also breed one of the males from the group you suspected was sex link back to a parent, or if it was just eggs from someone else, pair one of the roux hens from that group back to a sibling. You will want to keep silver out of the mix at least until you are certain which males are roux carriers, because silver can make it more difficult.