See the skull-and-crossbone bandannas? These are the bikers birds. They're bigger, tougher, meaner, and just generally badder than all the other birds.
When they show up, the other birds just go ahead and give themselves black eyes.
And according to my bird book, they don't even belong in this neck of the woods. But when you ride a Hog, you can go wherever you want.
They even bring their punk-spawn with them, indicated by the lighter colored bandannas.
Don't ask to see their tattoos.