Just to conclude the story... I shot this less than a minute later. I assume, months later while putting this together, that our intrepid gimbal shooter was going after a flock of snow geese. This tundra swan was part of a small flock of a half dozen or so that flew in amongst or on the tail of the snow geese.

I shot this with the same camera - D200 and 300/4 AFS - hand held, as the other shots in this gallery. I had a 300/2.8 + TC17 on a D300, on my own Wimberly, working 500mm but it should be obvious from this uncropped frame why I chose the hand held route. Even so, I had too much reach at 300mm - a rarity! But it happens. And this is why I always back up my gimbal and long lens with a shorter hand held camera. I doubt that I could have gotten the altitude needed for this shot even if I were working the gimbal at 300mm. This is one of those times when I would have been better off with the 70-200 + TC14. I might have had time to zoom out and get this shot without a clipped wing.