click this photo by Bert Spitz
Young male hummers (the adult males have all left) sometimes have a small cluster of tiny ruby feathers on their throat - the future gorget. In the right light it flashes like a bright red stoplight - a fragment of the future gorget. Here's a recent photo of this drop of blood by Mark Schaller:
And here's an older video of Fred's full gorget -note how it looks black from the side, but flashes brilliantly when he turns towards the camera.
There's still some availability saturday, sunday and monday (our LAST DAY THIS YEAR)