When I was on Great Duck Island, the breeding seabird island I mentioned earlier, I saw a black-backed gull kill and swallow a full-sized hare and swallow it whole- I think the hare had a broken leg or something already, because we just heard it scream, turned, and saw the gull stab the hare, pull out and discard its large intestine, and then swallow it head-first. My friend got digital photos of the gull with the hare's feet sticking out of its bill, its crop distended, as it tried to swallow something almost as large as itself!