All of us scan our feeders throughout the day and periodically see a hummingbird feeding, but is it the same bird? How many birds do you actually have? That is a question where I'm sure the answer would surprise many people. The females have a mission in nesting and raising the young, so they typically don't stick around the feeders for any time beyond a minute each feed. Then there are the males who have a pecking order. They will battle it out to see who outlasts each other to determine their choice of territory. The strongest and most courageous will pick his favorite location and determine how big an area he wants to defend. The next in line will choose his favorite of what remains, and so on down the line.
Once territories are determined, food can become an obstacle for those who are pushed out of the prime locations. They may be forced to steal what doesn't belong to them, and that could mean risking life and limb to get it. The fact is that many areas are limited for food, so numerous males could be seeking out the delicacy that can only be found in large doses within a feeder, and they may be few and far between. This is the reason I always suggest multiple feeders and well spaced out around your garden. It makes it very difficult for one male to dominate all feeders, and it allows several other males the opportunity to get in a feed with a bit less danger of meeting up with the dominant one.
So which one is the dominant one? Well that is always the one who wants to be seen. He will sit in the open, high atop a tree or post, and let every other intruder know that that's his territory and he's not afraid of anything. He wants to be seen, whereas the other males don't. Fidgety behavior of a drinking male can often times indicate he's scared for his life and will frequently feed in and out of the feeder like a woodpecker. The dominant male is usually far more relaxed. He takes his time feeding and lifts his head out of a feeder just to get a breath of air before overindulging with another glug of nectar. Watch for these habits. One wants to tell the world he's in control, while the others take a quick feed and leave the yard or hide deep in the tree and not atop it.
Here are a few far and near shots of Ziggy the dominant one, sitting as high up as he can to try and detect any thieving intruder or to spot a newly arrived female looking for a mate. N.E. of Edmonton, Alberta, Canada. May 28, 2018.