Several hatcheries (Mt. Healthy, HealthyChicksandmore) sell a RIR/Columbian Rock Cross. They are a RIR female with CR male. I have limited knowledge of genetics from HS biology, but why do the girls show the Columbian pattern & the males are columbian with brown/red wash in places? I take it columbian is dominate also. Is this a sex linked chicken? I would think not, as they wouldn't be different enough at hatch to be easy to tell. Has anyone ever had these chickens? They are supposed to be good egg layers & docile chickens. Why doesn't someone just sell a hatchery Columbian Rock? If anyone has ever had them, what is the size like? Thanks.