I would go out with a flashlight and look up in all the trees. Often I go to lockup my chickens and do a head count and one more are missing. I do a quick scan of the trees and there they are. I have to pluck them down and put them back in their house.
I hope you find him.
I haven't finished reading the thread yet so Im not sure if anyone has suggested this as an ID but I wonder if it is possible that this bird is a chicken guinea hybrid. It does somewhat resemble some I have seen. This cross is possible though the offspring are sterile.