The day after The Disappearance, I kept all the remaining birds in their, admittedly deluxe, run. It was rainy, which may have been a mitigating factor, but the birds stayed in the semi dark coop all day, huddled in the corner. Putin would glare at me, I'm not kidding, every time I looked in on them.
They just didn't seem happy.
So we had a family talk. Much of the reading and personal experiences about which I've read and heard all indicate the same thing - chickens rarely reach old age. One chicken blogger, who keeps his chickens in a run all the time, has never had one make it to the point where she now longer lays eggs. Most people I know with chickens have lost whole flocks to unseen predators, be it hawks or raccoons or weasels. In our way, perhaps slightly twisted, of looking at it, the chickens were likely to fall prey to some nasty creature at some point. The difference was how they lived in the meantime. They could either be in the run, confined, or in the fenced yard, relatively free. (And occasionally when their feathers grow out, completely free.)
We've opted for the slightly more dangerous freedom. So the remaining four girls are out and we don't know how long they will make it. That being said, we really didn't know how long they'd make it confined either. Don't worry, either way, I'm sure you'll get to read all about it.
The remaining hens:
Putin and Koch Brother I
Koch Brother II