Bee Hummingbird (Mellisuga helenae), perched. CubaThere are over 300 species. (Family Trochilidae, order Apodiformes.) The long cleft tongue of a hummingbird is in the form of a double tube, which can be extended a considerable distance beyond the bill and withdrawn again very rapidly; the sternum (breastbone) is greatly developed, forming a suitable base for the wing muscles; the plumage has a metallic lustre. .