Three weeks ago I bought 4 Americaunas and 3 Barred Rocks baby chicks. Everything seemed to be going well until tonight when the Barred Rocks cornered one of the Americaunas (the largest and fastest growing chick) and pecked on her until she started to bleed. Fortunately, I check on the babies often and caught it before it became too serious. I removed the wounded girl from the brooder and set her up in a separate box with another smaller Americauna so she would not be alone. I know a pecking order is normal but not to the point of serious injury (I didn't think). I have no doubt that if I had not caught this that they would have killed her by morning. Is this common when mixing breeds and what can I do?