Food can be scarce; unlike feeders, recently fed upon flowers are tapped out, so ideally a single bird will control a patch large enough to keep it going. During the breeding season you'll see the same thing with birds like robins, and in fact most woodland species. So yes, this is normal behavior.

I did notice another method last night at the feeder. Since the controling male pulled out a few days ago at least three young birds have been arguing over the feeder. I noticed one sitting nearby watching two others going at it full blast, the usual air show. As soon as they chased each other off over the roof he flew in for a nice long drink. So maybe aggression isn't the only strategy that works?
Is our species that much less aggressive? If you think about it I can guess what your answer might be. At least hummingbirds only consume current resources, and haven't, like one species I won't mention, figured out how to consume the future's resources too.

Good point ward! When they get to Mexico there will be so many other hummingbird species there. the non migratory ones will probably bully our rubies so they will be at the bottom of the hummingbird pecking order? Just wondering. Sarah

Food for thought Sarah.