These little guys show up each fall; I have watched them at my feeders for about four years and they are so interesting, as well as pretty. These individuals look so delicate!
According to the website Phys.org, "Previous studies by the UC Santa Cruz researchers showed that the patches of yellow and black plumage on the birds' heads serve as "badges of status," signals that correlate with fighting ability and allow birds to figure out who is dominant without having to fight. Birds with bold crown coloring are dominant over those with duller crown colors, regardless of whether the bold colors are natural or painted on by the researchers."
These guys sporting bright crowns certainly look like they're cruisin' for a bruisin'!
In fact, when this flock arrived, they chased off a crew that was landing at the same moment. A short, violent mid-air battle!
And then someone had to stand guard ---
While someone else fed his face!