The Canon 70-200 f4L even with a 1.4x TC is not really long enough to capture birds well; I didn't get it thinking it was, but sometimes in my back yard, the birds come close enough regardless...then I snap 'em as shown below.
These shots unfortunately were taken through our storm glass door. (It's much cooler waiting around inside.

)
I'm gonna have to set up a feeder real close to the house, or get me one of them Canon EF 400mm F5.6L lenses. I'll bet the feeder is cheaper.

but where'e the fun in that. :lol: