I don't really worry about light on the feeders, put your feeders anywhere, but close to a tree of bush where they can fly into if a mean ol Hawk swoops in. then go out and find a pretty and big branch that you like, dig a hole deep enough to support it, place that in the sunny area and shoot your shots of them on the perch instead of the feeder, makes for a more attractive shot. They like to sit on the perch and check out for predators or the dominant locals. pick out a pretty stick/branch. looks like you need a faster shutter speed, though 1/800-- should have produced better shots, trying to get those speedsters in flight without a lot of flash units is very hard. but I found that even the 7d as great as it is, still has a lot of noise (at least mine does), I try to never shoot above 400 iso, sometimes you can't help it.
Good Luck, lets see some more, and you are right thet are very fast movers. I also use the single spot af , usually 1 above the center with af servo.
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