It's fun to watch a kingfisher with a little bullhead. Because of the bullheads barbs, the kingfisher will thwap it on a branch repeatedly before they finally swallow it. They want to make sure it is dead before downing it. Yesterday I watched one beat a bullhead not 15' from me; I could hear the sound. He thwapped it for five minutes, swallowed it, then out it came again for another five minute beating. I saw a kingfisher catch a shiner a few years back and it was immediately devoured without tenderizing.