It's good I stumbled upon this thread ala Facebook. I've raised chickens multiple times but never had to integrate flocks. I have 8 two year old hens (third summer--4 red sex links, 4 black sex links) in a coop building (10x15) with an attached hoop coop (8x16). There are also 4 8.5 week old Golden Buff Littles. The Littles spent the first 4-5 weeks in a cage in the garage with a mama heating pad set up. We moved their cage (similar in size to a large dog kennel) into the hoop coop 4 weeks ago so they could start to get familiar with each other. Over the past 2-3 weeks, I have let the Littles out to see if they were ready to be together. Each time, it was clear the Bigs were NOT interested in playing nice, especially one of the red sex-links. Because the Littles were quickly outgrowing their crate, we divided the hoop coop with a 4' fence. Bad move. One of the Littles somehow got on top of the crate (3' tall)--which I never in a million years thought they could do yet--and she apparently jumped to the top of the fence and went over into the pen with the Bigs. This all happened at the early part of the morning and we had no idea there was a problem. The Little Miss could not get back out of the pen and the Bigs went after her in a big way, especially the red one. I realized there was a problem while just admiring them through binoculars from the house. I haven't moved that fast in a long time!!!! Unfortunately, my poor Little is now missing all the feathers and skin from the entire back of her head. She is being doctored and kept in a cage in the garage these past 3 days and is eating, perching, pooping, and doing all things chickens do so I'm hopeful she will recover. The dividing fence is of course floor to ceiling now. That dadgum red hen paces along the divider fence just itching to get at the other 3 Littles. We don't know what to do now to integrate...or if they can be integrated. On top of that, there are 3 Littles growing as pets at a friends' house that are supposed to come live here in the fall (same exact age as my Littles) so we're going to have to do the whole integration thing yet again. I have tried squirting the Bigs with water but it's not making much difference. The options seem to be to cull the flock of Bigs (getting 4-5 eggs daily) including the mean red mama, get rid of the Bigs completely, or ______....
Other than our major mistake of the too short fence, I feel like I've done things as near to 'correctly' as I could have...other than getting the chicks down to the hoop at a younger age; but that was something I needed help with, and beggers can't be choosers on timing sometimes. I need to read further into this thread to see what pearls of wisdom lay inside but wanted to put our story of sorrow out there to get some possible suggestions and to warn others that it's a challenging feat. Thanks!