I had bought a wooden dowel at Lowe's that was long enough to go through one side of the wire to the other side, and of a diameter that would fit snugly through the wire walls. This worked well for quite awhile because I could slowly "raise the bar" LOL as they got bigger. It was long enough to extend far enough beyond the coop to be stable.
The chicks are 9 weeks old, and it seems like it is too small of a diameter for them now. I like the idea of a branch inside, but really don't have an area to screw it in the run, and since I move the chicken tractor to new ground everyday, I can't stick in the ground either. They have 2 square roosting poles in the nesting area, so I think I can just call that good? Or is it important to have roosting poles even though they are free ranging and could do that anytime they wanted outside? (But they don't - they mostly hang out in the long meadow grasses or under bushes and trees...eating wherever they are!)
They are outside and could fly into any low bush or tree, but they have never done that.
I love the chicken tractor I made - it definitely mitigates chicken poop pile-up, and I have an area right off the lawn that is wild meadow, so they love it out there, and I don't have to worry about doing anything with the waste (it just naturally dissolves into the soil,) after I move it one chicken coop width a day. By the time I get to the "end of the run" I will just start over moving it from the beginning again. One important point, move the coop towards the door that you usually access the coop interior on. First time I went the other way....and once I saw the ground where I would have to access the interior, I decided I was definitely going in the wrong direction, and moved the coop to other end of the run to start. The idea was, that by the time I revisited that area, all the poop would be GONE, not freshly deposited.