I put a wooden ramp in my coop that goes from the ground to just below the top run of a 3-rung perch (maybe 3.5' off the ground?). My silkie walks up the ramp and hops up on the top perch. She's often the only bird that will go up there. My cochin (who also does not like to fly or hop high) uses the ramp to get to the top rung, and walks along it to hop onto a perch that's perpendicular to the silkie's spot. It's cute how ladylike the two of them are, as opposed to the other birds who flap and fly all over the coop to secure their favorite real estate.
