OK, here we go...
This first one is his door perch. I made this myself, with maple dowel I bought and drilled. He doesn't spend much time on this one, it's mostly used for transit in and out of the aviary, which is 5x5x7':
This next one is his sleep perch where he spends the night. It came out of his original smaller dome top cage, and I put it up high, so he'd feel safe sleeping on it:
This third one looks towards the back of the aviary. The branch is from a few cottonless cottonwood trees that I planted in the yard a few years ago, which are now about 30' tall - very fast growing, and I found out safe for birds, so we have a nice supply of branches for him to play with and chew on now.

The rope perch is 1"D, I think, and he has the spiral bungee too:
This last photo is the maple perch I gave him in front of the food dishes, and a concrete perch to the right there. I think the only thing we don't have, is a concrete slab that you mentioned, which I can probably get at Home Depot:
So with all this, why would he have a callous?
