None of those are bad, you are being far too hard on yourself. Never forget that we tend to show the world our best shots, not our worst.
AI Servo is the wrong choice for the first two and at least in the first shot, the grass directly behind the bird seems sharper than it does. That might just be due to AI Servo, or could indicate other problems. At least one shot was against the light and internal lens reflections have caused a problem while the last one appears to have been shot through glass because there is an odd angled reflection at top dead centre?
We all have shots that we wish we had done differently, hindsight is a wonderful thing. But if you can figure out the reason a particular shot did not quite make the grade, then next time it has a better chance. I like to think I learn every time I go out with the camera.