I have these two 7 week old Marans chicks and trying to figure out gender. I have a third black chick, but the problem is I don't know if the third chick is langshan or marans. The third chick has a yellow comb which is tiny compared to these guys. I have a splash cockerel the same age bit he is 15% larger and came from a different breeding pen, otherwise I don't see the difference. There's pictures of two BCM chicks here. One is very slightly larger.