Humming Bird

Hummingbirds are indeed the only birds capable of truly flying or hovering backwards. They are able to rotate each of their wings in a circle, and this enables the hummingbirds to fly forwards, backwards, up, down, sideways, upside-down and even hover. For this reason, hummingbirds are also known as 'King of fliers'. 

However, other birds have been observed fluttering backwards. This is the case with some warblers when they feed. Waterbirds such as herons and egrets have been observed fluttering backwards when they are engaged in territorial disputes and the dominant bird gains the upper hand. This is only short-term, unlike the sustained backwards flight of the hummingbird. Birds such as kestrels and terns, which hover by flying into strong winds, actually fly backwards in relation to the ground, but forwards against the wind which is pushing against them. The Roller pigeon can turn somersaults in mid-air as it catches insects in mid-flight.

Hummingbirds are the only birds that can fly upside down. They do so because of their angled wing structure. However, a hummingbird can fly upside down only for a short period of time. A hummingbird can also fly backward; it does this when removing its bill from a tube flower.