I agree, Roger, that a Rufus has an attitude problem. They demand to be king of the hill and will run off lesser species trying to share a feeder. I've had modest success by using two feeders separated as far as possible. A single rufous will drive himself nuts trying to dominate both. Just as soon a rufus concentrates on one feeder, lesser species will swoop in on the other, if only for an instant or two. And round and round they go. But a rufus soon learns to position himself in a tree or bush halfway between the two feeders and efficiently launch an attack on either one.
On a related topic, it is possible to partly train a hummer. At my Colorado cabin I was able to get an occasional hummer to land on my finger when held horizontally motionless just underneath the feeder. It seemed to me that the hummers up there in that rather remote high altitude location were less fearful of humans.
Fascinating creatures.
CJ