Archilochus alexanri male. He was courting a female in a dense oak grove by performing a small-scale (2 meters at most) diving display that reminded me of a swinging pendulum. Then he would land on the branch above and mechanically rotate his head back and forth, possibly to flaunt his brilliant purple gorget. They never actually did copulate, although I didn't have time to wait, either, as I had to be somewhere and was in a bit of a hurry. I'm guessing they did, though. The weather was pretty drab and cloudy, with light sprinkles.