That helps a lot. With no other roosters that makes it a lot easier. Since he is not a really young one, that also makes it easier, especially with the older hens in the flock. Older hens can get pretty brutal to a young adolescent rooster, but since he is mature, that is not an issue.
I’m not going to tell you what to do about quarantine. That’s a personal decision. Different people do different things.
I’d just turn him lose with the hens. In most integration situations I’d say house the new chickens next to the existing flock so they can get used to each other. But I really don’t think that is necessary in your case.
What should happen is that he will immediately mate with some of the hens. That shows his dominance. Your existing head hen might put up some resistance, but since he is mature, he should be able to sway her and assert his dominance pretty easily. That mating ritual is a dominance thing as much or even more than a sexual thing. The one on top is showing his dominance. The one on bottom is accepting that dominance.
There is a reasonable chance this will shake up the pecking order a bit, but probably not much. You might even see the rooster breaking up those pecking order fights between the hens to keep order in his flock. That’s one of the duties of a dominant rooster, but the other hens have to accept his dominance so he can do that.
There is a much smaller chance that your head hen will not accept his dominance and try to fight him for it. That does not happen that often. Quite often the dominant hen becomes his best buddy but they are living animals so you never know for sure what will happen.
I’m not going to tell you what to do about quarantine. That’s a personal decision. Different people do different things.
I’d just turn him lose with the hens. In most integration situations I’d say house the new chickens next to the existing flock so they can get used to each other. But I really don’t think that is necessary in your case.
What should happen is that he will immediately mate with some of the hens. That shows his dominance. Your existing head hen might put up some resistance, but since he is mature, he should be able to sway her and assert his dominance pretty easily. That mating ritual is a dominance thing as much or even more than a sexual thing. The one on top is showing his dominance. The one on bottom is accepting that dominance.
There is a reasonable chance this will shake up the pecking order a bit, but probably not much. You might even see the rooster breaking up those pecking order fights between the hens to keep order in his flock. That’s one of the duties of a dominant rooster, but the other hens have to accept his dominance so he can do that.
There is a much smaller chance that your head hen will not accept his dominance and try to fight him for it. That does not happen that often. Quite often the dominant hen becomes his best buddy but they are living animals so you never know for sure what will happen.