Brad, Cecil Baird has suggested that a very large "Bluegill" that I caught in my pond could be a Redear Hybrid. I can tell you that it is the biggest "Bluegill" that I or anybody I know has ever seen. If your Redears are crossbreeding, you may have some pleasant surprises in store for you. If you would like to see a picture of the fish, send me your Email address.
Jim