My Freddie is my only hunter. It was interesting to watch. He started as a young Tom by hunting blood worms - big, nasty, slimy ones. He brought them home in triumph and devoured them in front of me.
I was grateful when he moved on to mice, voles, and even an occasional bird. He prefers squirrels and chipmunks, I suspect because they are the hardest to catch.
I have no bird feeders - that just wouldn't be fair. And my neighbor lets her dogs loose when she sees Freddie sitting under her feeders. My biggest concern is disease. The birds he catches are either stupid or sick and that worries me.