Just to add to Jay262's info re: foxes. Had a Red Fox come right out of the woodline, grab up one of our Gold Sex Link Pullets, and take off. Pullet immediately went into shock (legs/head swinging limply from either side of fox's mouth). Was standing about 10ft. away from the grab and immediately rushed the culprit. Fox dropped what I thought was the dead pullet as it tried to find an escape through thick brush. Fox disappeared and the pullet had miraculously revived, from a pile of `lifeless' chook, by the time I got back from the chase. If I hadn't seen the rush, chomp and run, I'd never have found out what had happened (not a single feather dropped - pullet only required four stitches).
Hope your hen returns!
Hope your hen returns!