disappearing chicken

I have (had?) A Brahma hen just over a year old. She disappeared without a trace well over a month ago, and after asking around the neighborhood, I figured that something had taken her. I was sad, because Beatrice was one of my favorite girls (a lot of sass, that one), but I made my peace and...

I have one chicken who disappears for days at a time. She hops the outer fence and I assume she has been taken by a predator, then she shows up 2-4 days later to join the flock and eat. The rest of the flock behaves naturally when she joins them. Then, she seems to just disappear and I won't...