Earlier this week I visited a frozen farm pond and discovered a puzzle. The owner of the pond had scattered feed corn onto the ice, and all around it in the thin layer of snow were footprints. The corn was uneaten. The footprints were shapeless since no impression was left in the ice, so only size and gait could be detected.
Raccoon and possum are the leading candidates, but both would surely be happy to eat corn. The gait ruled out a hopping creature like a rabbit or squirrel, and the prints and stride were too small for a fox or coyote.
There was one more clue, a box turtle on the ice about five feet from the shore. It seemed to have crawled out there and simply stopped. I retrieved it and discovered that it was partially eaten. Its shell had been damaged some time in the past but had healed over and continued growing, but the wound left a gap where its right shoulder would be if turtles had shoulders. The head and right leg were gone, but the rest of the turtle remained. It weighed as much as a live turtle would. Something managed to get its mouth into gap in the shell and bite off the leg and head.
Pondering the clues, this is what I believe happened: the wounded turtle was feeding on the corn, the noise drew the attention of a feral cat, which was desperate enough with hunger to persist with the difficult meal.
Update: I returned the next day to find fox tracks across the pond and around the dead turtle. It was likely a fox that dug up and ate what it could of a hibernating box turtle.