Hummingbird yawning

We have a resident pair of anna's hummingbirds. They hang out by my office most of the day. Sometimes they chase each other around, sometimes they drink from a couple of nearby feeders, but mostly they just sit and occasionally clean themselves. They don't mind me getting close enough for a photo, but they do sometimes become impatient when I have to clean and fill their feeders. They'll either sit on a tree branch pouting or they'll "buzz" me. I am looking at him now while I write this blog.