It’s a little-know fact (at least, I didn’t know it, so I assume it’s little-know) that hummingbirds are big jerks.
We put out a feeder this week, and it immediately attracted a number of tiny birds, but, to our surprise, they refused to share. Whichever one got to it first would camp there, occasionally taking a sip, but mostly just sitting, waiting for other hummingbirds to come. And when they did come, the first bird would chase them away.
The back yard is now the scene of an ongoing game of “king of the hill” with one bird or another guarding the feeder until the others gang up on it. Then a new bird claims the vacated perch.