So here we have a blue jay, which is of course a  passerine bird in the family Corvidae, native to eastern North America.  If you know how to pronounce these words, and see a blue jay and want to impress the shit out of your friends, you can be like “oh man look at that Cyanocitta cristata” 

They are NOT going to know what you are talking about, but that’s what a bird flex is.  When you drop some facts about a bird that some casual bird watcher would NOT have access to.  That’s how you get respect in the bird-watching community.  

Look at the detail on this beauty: