Fantastic.
Browsed though this thread a few times now, I am in awe of how many fantastic bird shots there are.
It inspired me to try some. Rented a Canon EF 100-400mm lens for the weekend to play with. Took the dog to the park and played.
I now have even more respect for bird photos - there was only a couple chickadees and 1 woodpecker, but of the 50 or so shots I took only one is.. half decent.
Not same league as people here, but my best so far.
Edit: Shot with canon T2i, Lens 100-400mm, f/5.6, 1/2000 sec, ISO 800, hand held