So, I have a small flock of about 11 hens in my backyard. They have about half the yard fenced off for their run, and then the rest of the yard is what I call the "main yard" which is just our typical backyard. One of my oldest (and favorite!) hens is an Old English Game Bantam (named Buttercup) and has always been very intelligent and high in the pecking order, despite her tiny size. She's about 3.5 years old now, and just recently (maybe about a week ago) she started CROWING. Roosters aren't allowed in my neighborhood, so I'm concerned. I went out the other day to investigate and noticed that she seems to be going through a HARD molt; she is full of thick, big pinfeathers all in her neck, necks, chest.... everywhere. I can only imagine how uncomfortable she is. I figured maybe she would stop crowing when she felt better, but in the meantime I took her out of the chicken run and put her in the main yard (with a very spoiled and friendly EE pullet who is about 12 weeks old), hoping it would 'knock her down' a few pegs and maybe curb the crowing. Well, the crowing got better for a day or two, but today I heard her crowing just a few minutes ago. I went out to investigate and saw her WHOLE FACE is scratched and bloody. :C I mean, it looks like aggression marks but the idea of my chick causing this damage (especially without any marks on her) seems very odd. I thought maybe it was a cat or something, but in the few minutes I was out there, Buttercup slipped back into the chicken run. I was just going to leave her in there with her friends when suddenly she was instigating fights with several of the other hens. Withing SECONDS of turning my back her and another hen of mine were going at it full-tilt, and Buttercup's wounds all came back open. *SIGH* So what gives? What's with all this sudden aggression? Is she going through chicken menopause? She hasn't laid in quite a while, but she's never been a very good egg-layer.
It seems it happens sometimes when there's no rooster in a flock, a hen will start to take over the role, and it sounds like your little girl is stepping up. I have a theory that they start to crow in order to draw in a rooster to the flock. I don't know what you can do about it. You aren't breaking any laws as you don't actually have a rooster. I would probably return her to her original flock as removing her has caused fighting, and I would let them settle it.
I have an older hen crowing....and I have a mature cockbird too.....it can happen but is fairly rare. The fighting, and resultant wounds, was the result of integrating two birds that had been separately housed not wanting to share space. Then she had to regain her pecking order status when she got back into her old area. They won't lay when molting, but it's odd that she's fighting while molting...they often are not feeling great and often isolate themselves and rest. She's a feisty one I guess. Don't think you can stop the crowing and not sure how to handle your 'rooster' bans.
Individual temperament enters into this equation. Buttercup seems she has a feisty personality, even during times she's not even feeling up to par. You may need to segregate her until her aggression tones down. I have three hens who like to crow. One will do it for months at a stretch, then stop. Another will spend an hour at it on some days, then she'll go back to just being her vocal, complaining self. A little understood biological fact about chickens is that they possess both male and female sex cells. This permits them to display sexual characteristics of the opposite sex at any time. It even allows a chicken, under certain extreme conditions, to actually switch sexes, though this is extremely rare. I don't think you can do much about the crowing other than to try to discourage it by giving her a quick poke on the back when she does it. The saving grace is that hen crowing lacks the volume that rooster crowing has, and the sound doesn't carry nearly as far.
