We just brought home a new hen and our roo charged her with his wings out and low and looked like he was trying to kick her or jump on her. I'm assuming this is normal establishing dominance kinda thing but when should I worry
The best thing to do when bringing a new bird into the territory of an already established bird if you aren't going to quarantine is to keep them separate in a way where they can see each other without having any contact for a few days. This can be doneby creating a pen with chicken wire, keeping the new bird in a dog crate, or whatever else. If they have time to get used to each other there is less of a chance of one of the birds getting seriously injured. Since mine free range I keep a small dog kennel in the yard for new birds to hang out in for a couple of days. Then my flock can see them and challenge them from the other side of the fence but can't hurt them. Usually they calm down after two or three days an everyone can be integrated. Good luck!