When I lived back in the Eastern US, I was at an outside event, watching a swan and some ducks on a small lake. The swan proceeded to begin to drown the baby ducks by grabbing them behind the head, and holding them under water until they drowned. I tried to save the ducks, but the swan came after me. I was literally punching the thing, and it was giving back as good as it got.
Swans, apart from the myth of being beautiful elegant creatures, and haughty and just plain mean [territorial].