But really, that's what I use for my girls and boys. We logged our forest almost a year ago, and a few of our conifers were decently thin, so I cut two to 14 feet and put them up in the coop. They're better than 2x4s to me because they're a lot more natural and round, not so uncomfortable and edgy.
Fir stair banisters from Menards. Cheap and they come in 8 ft., 12 ft., 16 ft. Easy to mount with the bottom side being flat. Mine worked out great. I have a free floating 8 ft at the end of each coop and then 16 ft over their nesting boxes.
I also use 2x4 wide side up because it gets cold here and their fat bodies can cover their feet real well. I also like the idea above of using a natural tree branch. Wonder if their is greater likelihood of parasites or other small bugs whereas the 2x4 are kiln dried?? I have no idea?
Of for my OEG I use 1 inch dowel rods. They used to roost on small tree branches in the trees. Took me 2 months of being locked up to roost in the coop.
What size do folks use for bantams? I've got 6 chicks
ETA---My Bobwhites don't really roost. But they do like setting on a 6 inch board up high. I think their fat little bodies stop them from really roosting.