Rufous-tailed Hummingbird

The buff bellied's green coloration ends much farther up the breast. The lighting doesn't show the rufous tail, but it is the only similar hummer. These birds probably folded their tails which would give another impression.

There were no buff bellied that I saw. The other rufous tailed were much bigger and broader.... that's a better guess than most.

Genus Amazilia, either Rufous-tailed or Buff-bellied.

also from the cornell site: The Ruby-throated Hummingbird is a small hummingbird with a slender, slightly downcurved bill and fairly short wings that don’t reach all the way to the tail when the bird is sitting.

Not seeing it. Ruby throat is a stouter bird and the male has a ruby throat, female a white or slightly speckled one