I thought this was a very good video about hummingbird flight. It is pretty amazing how hummingbirds have so much dexterity and maneuverability in the air. They can even fly backwards and upside down!
At about 1:35 scientists are performing the same experiment as in the paper I read, where they attach a string with weights on it to a hummingbird and see how many weights the hummingbird can lift.
If this link doesn't work, the video is called NATURE | Hummingbirds: Magic in the Air | Hovering | PBS