Birds... Fast Birds... Focus Help Needed w/7D 70-200 f2.8 USM IS II

Can you explain to us how you have the camera set up?

-AI-Servo

-single AF point or AF point expansion. This is effective when it is difficult to track a moving target with a single AF point. It is less prone to mis-focus on foreground or background as will some of the other multi-point  AF modes.

-high speed continuous drive mode. In my experience, the first image is usually a bit soft but as long as you track the moving subject, keeping the AF point on the subject , the rest will be in focus.

-Ai Servo tracking sensitivity set to slow to prevent any temporary obstacles from changing the focus tracking from the present target

- AI-Servo first and second image priority. set to zero, AF Tracking on first shot with focus tracking on second and subsequent frames

-AI Servo AF tracking method, set to 1 if you expect objects to come between you and the target.