Which are the only birds that can fly backwards?

The hummingbird, such as the broad-billed hummingbird, is the only bird who has the ability (and tendency) to fly backwards! These tiny birds can beat their wings 53 times a second and they fly in a unique acrobatic style matched by few other birds. They hover often, beat their wings extremely fast, and they also fly upside down as well as backwards. Most birds fly by moving their wings up and down, but hummingbirds have a much more complex style. They are able to twist their wings while flapping up and down, similar to the style of dragonflies. This unique movement allows them to fly backwards.