Males of any species will dominate over the females. (You have testosterone to thank for that.)
Older birds will dominate over younger members of the species because they hold better odds of procreation. (“Step aside, junior.”)
And larger birds will dominate over smaller ones because they have greater caloric needs. (Therefore, a female Northern Cardinal will gladly tell a more diminutive male House Sparrow to get bent.)
Amazingly, this endless cycle of dominance almost never leads to physical altercations. (Seriously, when was the last time you saw a bar fight break out at your feeder?) Instead, birds use a series of non-violent “threat displays” to signal their intent. That’s what’s happening when a Blue Jay flares its crest at a smaller bird or a Red-Winged Blackbird tucks in its neck and puffs out its shoulders like a football player on picture day. The result: the more dominant birds feed and depart, allowing the smaller displaced birds to get their fill (eventually.)
As for the lack of violence, that’s part of nature’s plan, too. Birds are delicate, precision beings. And even the winner of a hard fight that has a broken leg or damaged flight feathers will most certainly lose its life. Simply put, it’s just not worth it.
So, enjoying nature’s clockwork-like precision at your feeders. Every bird will get a turn. Even if it involves a little “bullying.”