Shots below are:
1. Full frame changed resolution to 1440x960 - 5d2, 70-200 F4 LIS, @200mm, F4, 1/1000, ISO 400. In PP +0.3EV and other.
2. 1/4 of FF square cropped to 1440x960
3. 100% crop at 1440x960
This is not a good picture BTW but what I see here, is that depending on the bird's behaviour you can get sharp or blurred photos with same settings. Here we have a bird landing on a water fluttering it's wings. The whole bird except the wings is perfectly sharp in my opinion. If the bird was in steady flight, then these settings would be good enough. The wings are partially blurred because of the DOF, mostly because of the shutter speed. If I wanted to have those wings sharp too, the settings should be somewhere around 1/4000s and F5.6-8. BTW it would push ISO to 3200 at this light which was there :-)
But this is 200mm, not 500mm....