A species I haven't seen, thanks for sharing him. Easy to see where the name came from!
The natural background is excellent, and the lighting on the plant is good, but a bit too much of the hummer is shadowed for my personal taste. A bit of off camera flash, or even a bit of reflector work if the circumstances allowed, would have really opened up those shadows.
I would consider cropping in from the right, as that area doesn't add a lot to the image. You could then do a small crop top and bottom to keep the proportions the same if you choose to do so.
Killer species, flower, natural BG and feeding behavior. That said, this bird's head doesn't look sharp to my eyes. I don't think 1/640sec is fast enough for HB photography, and I think you would have greatly benefited from using flash here.