Pity about these shots - the best birding shots are when the wind direction is heading towards the Sun - that way you have natural light hitting the face/body of the bird. As an example:
http://www.macro-images.com/images/B.../F79C9391.html
I don't usually shoot birds at all, and the seagull shots on my pages were the first attempts at BIF. Mind you, I was using a 1 series camera, where the AF is far superior to the xxD range of Canon cameras imho. It *does* help.
Have you considered trying to get a copy of Artie Morris' books on bird photography?
http://www.birdsasart.com/
if you're lucky, you'll be able to pick up the first edition on the 2nd hand market (not likely, people don't usually part with it). His 2nd edition was released only on a CD, but is very well priced and really worth buying. He's a brilliant bird photographer.
The lighting in these shots is simply from the wrong direction, and it makes it very difficult to show details in the bird(s). Yes, you could use highlights/shadows, but that can only do so much.
You did a pretty good job with the 40D and 250mm lens too, well done. f7.1 was never going to help your cause. Why not consider a 2nd hand 300mm f4 (non IS version, it's optically better than the IS version imho)?
I wish I could see birds like this!
Dave
