Bird should have been centered and with a canon 20D you should be getting much better sharpness than this, but I am assuming you are a new to your camera,practise and more practise and you will get the hang of it.
Yes I am new to the camera, only got it for christmas. I also took my 2 and 3 year old to the zoo with me, and they get bored if I take too long...a tripod is out of the question when I have them with me. It also doesn't look as sharp when downloaded to view on here. I need lots of practise, thankyou.