I have a pullet that appears to be a rumpless genetic "sport". That is, she appears to be rumpless due to a genetic mutation, rather than a recessive trait. Or at least she is the only rumpless bird out of all the ones I've hatched. Nor have I heard from any buyers of my hatching eggs of any rumpless birds hatching. I did a little research and it I understand this can happen from time to time. My next question is, am I correct to understand that if she is truly rumpless, she should be carrying a gene that is dominant for rumplessness? If so, it would follow that one could start a rumpless breeding project with her and any rooster(s), rather than it making sense to breed her back to her father. (Since rumplessness is dominant and if her father was carrying it, he would be rumpless).