I've had several transgendered and a couple of transsexed hens/roos.
Gender being a social role.
Sex being more biological male/female aspect of things.
A transgendered hen will adapt a male role in my flock if she is unhappy with the current rooster. Rooster originally meant "ruler of the roost" and could be male or female. She'll crow, take on the defence role, keep the other hens in line and the like. All the things a rooster is supposed to do to keep the flock healthy and safe. Once I replace the weakling cockerel with a strong one, he'll take the rooster role and the hen will go back to being a hen.
Of the ones that were transsexed, I had one fella called hobble foot (I use the male pronoun with this guy because that's what he liked). When he was a young hen, he escaped into the bachelor yard. They were very excited to see a sexy young girl and poor old hobble foot was very badly injured and could not walk for many weeks. We kept him in isolation and for the first few weeks he remained a hen, lay eggs, was henshaped, hen behaviour, all that. But after about a month, he stopped laying eggs and became cock shaped, had a beautiful deep crow, and once he could walk again, took on the full role as second cock in the flock - including mating with the girls. I had hoped to experiment to see if the eggs were viable but alas, he only lived a couple of years and I never got around to it.
Is there a way to tell for sure which hen is next lowest in the pecking order? I think it's my Orpington, but I'm not 100% sure.
I was worried about and looking for physical illness, but not behavior changes. I feel like a dumb now.
We do not have a rooster. This is my first flock, and I didn't feel confident enough to get a rooster with the hens. Or to get straight run. I didn't think of a banty; I'll keep that in mind. Apart from the lack of confidence, we do live in a neighbourhood, and I don't want to cause the neighbours undue annoyance.