chickens are racist

All the white hens in my village follow the white rooster. And all the brown hens follow the brown rooster. Or maybe the white rooster only lets white hens follow him. Or the brown rooster only wants to mate with brown hens. Maybe this is common knowledge, but I've never lived in a place that had chickens roaming around freely so I've never noticed this segregation before. Now I'm pretty sure that ancestral chickens weren't white, so where did the preference for white roosters (or white hens) come from? Maybe there's something else going on that I haven't noticed. Maybe the people that own the chickens have somehow convinced them to stay segregated, so in that case it's not really the chickens' choice. I'll let you all know if I find out more.