I drive by a red wing blackbird spot every day for work and thought if I ever got a long long lens I would shoot them. I got my 500mm f4 last week so it was time. This spot is great because they are well habituated to passing cars so if you stay in the car, they come within 5 feet. One nest is about 15 feet from the main road with 2 babies in it. Next on my list is yellow headed blackbirds. There is a fun video link here I shot with the 7D. If you pick the 1080i version it looks pretty sharp.
Red Wing Black bird