Ah yes, the male rufous hummingbird. Despite their diminutive size, they are notoriously aggressive and very quick to claim an area of their own, fending off any who dare intrude.
This little bully decided one of our hummingbird feeders at our campsite was his and his alone. He would sit in a nearby tree, standing watch, and the instant another hummingbird tried to eat, he would dive at Mach 1 and chase off the other.
The fast action was very tough for me to capture but I did get lucky with this one, catching him as he zoomed by in pursuit of an intruder.