Gosh, I just read this. I'm sure you are panic striken. I would be too.
I don't think you would have found him in the dark. He would probably stay put.
If you didn't find feathers or _____, that's a good sign.
He might have taken shelter in the rain. Is there anywhere that he could have been closed into or stuck in?? A friend of mine said when she was a little girl, the roo got closed in the feed can, and jumped out at her dad that evening!
Another thing, he might have gone up high to roost and can't get down. My roo did that once, got on the coop roof, and I had to get up there and rescue him.
Could he have gotten tangled up in something ?
Maybe walk around shaking some feed in a can?
Karen