Late last week, I was photographing a Tundra Swan when a large Mute Swan suddenly swam up to it. The classic fight or flight dilemma... The Tundra Swan elected to flee and did so post haste. Interestingly, he elected to fly straight at me! I managed to capture several images of the Tundra Swan in flight. I could feel the wind rushing from under his wings as he flew by a few feet over my head.
Morale of the story: always be ready for the unexpected...