Integrating 8 weeks olds to 16 week olds

[C Siena]

We have 7 pullets and 1 cockerel (RIR), now 15.5 weeks old, in an 8x8x8 coop with a 12x7x5.5 run. We hatched on 7/2 (8 weeks old), and have had the youngest chicks in a cage 3" from the run for 3 weeks 2-4 pullets and 3-5 cockerels, we're not keeping all the cockerels, maybe 1 .
Today, I set up a net barrier inside the run, thinking it secure enough as I watched them for an hour and not much interest in each other. Well a few hours later I go out to check (about every 30 minutes) and 2 older pullets are in the section with the youngest and 1 young one got into the section with the older ones. The RIR cockerel was going after the small pullet chick. I got her back to her area and secured the area where she pushed through to the other side. The 2 older pullets were doing fine with the young ones but I put them back and secured the top, I hope. So far so good.

My question is do I have to be concerned about the RIR? He has been testing his vocal cords for 2 weeks and about the same time, mounting the others. Is he just maturing early? (my Buckeye roo did not begin this soon.) I did not wait to see if he was trying to mount her but to rush to get her to safety. I am hoping to be able to integrate them together in a couple of weeks. What do I need to watch for? tia

 

[sourland]

I'd remove the RIR cockerel for a couple of weeks until the integration has been completed.

 

[C Siena]

I was thinking of keeping it this way as he is not the one trying to get through And I have no where to place him. I will also place loads of extra food with the older ones, in case they want that...but the grass is always greener on the other side.
We are looking for a used small coop/run to use for quarantine or time out. When we do fully integrate them, if I have to and it's not hot outside, I'll leave him in the coop with the others out and/or maybe put him in a large kennel.

 

[C Siena]

I'd remove the RIR cockerel for a couple of weeks until the integration has been completed.

Would you leave them as they are for 3? more days? Then keep the cockerel in the coop, while the rest remain in the run? I say 3 days as the temp is supposed to be in the 90s and then by Sat, the low 80s-mid 70s. Though the coop is in the shade with enough ventilation.

IF all goes well and the rest are getting along in the run, of course with a bit of squabbling/pecking order activities, and plenty of water/food stations and a hiding place or two...when would you allow all to be in the coop overnight with the RIR cockerel? 1 week? 2 weeks? longer? I am more concerned with the size difference. When I do, I will have to put hiding spots in the coop and let all out very early, so no commotion in the morning.
Thank you for your help!