I went out to the yard once only to find that pretty much all my ducks were gone! Within a few hours, one neighbour was herding a bunch of them back from her place across the road, another neighbour about a half kilometer away drove over to ask if I was missing a duck which I promptly went and fetched, another bunch were found huddled in the woods, and one was found stuck in the swamp the next day and I had to go fetch her. Very few came back on their own, I had to find them.
I had chickens in trees for days.
A fox had gone after them and they all scattered in every direction.
I don't think I lost any (that time).
Keep looking, they may surprise you. And keep *listening*. That's how I found the one in the swampy area and those in the woods.
Welcome to BYC, I hope to hear better news from you.