A little while ago one of our chickens went missing. She was getting old and was nearly totally blind and had often disappeared before only to turn up again. This time she didn't come back, so off I went for a little walk to try and find her hiding under a hedge or in an outbuilding.
I did find her, after a fashion, or at least the remains of her. She had been taken by a fox. This, and a few other piles of feathers were all that was left. Since she was blind she probably didn't know that a fox was about to get her and hopefully it was quick. She was a big girl so would have made an excellent meal!
One of the characteristics of a fox kill, apart from the pile of feathers, is the damage done to the feathers themselves. Foxes just rip out feathers in mouthfuls so the ends of feather always show the same kind of damage - ragged, torn ends to the feather shafts.
I also tracked the culprit for a short distance until it had gone through the hedge onto other land.