Selectively naughty rooster…

[lagrange chicks]

I’ve been researching my head off trying to figure this one out but I can’t really find any information and I’m very new to raising chickens of my own. I have a mixed age flock of 25 (24 hens/pullets and a single rooster). About a week or two ago, my gentlemanly roo became not so gentle with one single hen. She used to be his “favorite” lady but he suddenly started keeping her away from the rest of the flock. He’s a 6 month old light Brahma who is the absolute sweetest guy to people and normally to all of the girls. The main group of ladies he’s with (including the one he’s bullying) are the same age and all were raised together from a day old by me. The remaining pullets are 6-10 weeks old and he doesn’t pay much attention to them. For some unknown reason he just started chasing her away and sort of grabbing her by the back of her head (and not like he does when mating). It’s like he’s just slinging her head and then he goes at her feet first real quick, almost like he’s literally pushing her away. He’s not causing feather loss or drawing blood and he still mates her but she’s afraid of him and can’t hang out with the rest of the flock because he won’t allow it. I put him in rooster time out yesterday, where he still is, but will that be enough to correct his behavior you think? I’m just at a loss because he’s such a gentleman with everyone else. Why the one, single hen? Btw, they free range on a good sized property and have many hiding places. They’re only in the coop (25’x20’) at night where, surprisingly, he’s not too mean to her. If she catches his eye from across the yard though, he races towards her. Sorry for the lengthy, scattered post but I’m trying to be sure to include as many details as possible! Any help would be greatly appreciated.

I had the same the same thing going on, Roo would keep 1 pullet from the food and pick at her pretty bad, a week ago today I see him standing on her back and pecking her really bad in the head (saw this twice that morning). When I got down to the coop she was hiding in the corner with her head tucked/ hidden, her head was badly swollen and dried blood in one nostril. That was all I could take of that and culled him, he was my favorite of my 8 chickens but can't have that going on in a 6 x24 foot run, no free range here. He was a total sweetheart to the other girls and kinda wish I would have rehomed her since she is still picked on by a couple of the girls. Hope it works out better for you than it has for me.