You need a greater depth of field - to do that use an aperture of f/8 or smaller. You can get a depth of field calculator for your smart phone and learn how to adjust your aperture depending on the focal length of the lens, and the distance to subject. It also varies by the camera's sensor size. I use F-Stop app (free) on my iPhone and it allows you to key in your specific camera.
For example, I set it for your 7D with 200mm lens at 20ft from the bird, and an aperture of f/5.6 only gives you sharpness of 4"" in front and behind your focal point. At f/8 the sharpness increases to 5.4" in front & behind. And at f/16 it is 10" in front and 11" behind. Increase the distance to the subject also increases the depth of field but then the subject is smaller. Lots to consider. In general, for photographing birds you'll need a much longer telephoto lens. I use the Sigma 150-500mm and sometimes that's not enough.
Get the phone app and play with it.