The ostrich is the largest bird in the world. The hummingbird is the smallest bird in the world. Ostrich is available in black, brown and white only. The hummingbird has a green, blue, red, yellow, ostrich with his mouth wide and flat. A hummingbird's mouth and pointed. Ostrich with long necks hummingbird with a short neck hummingbird has the ability to store and release energy in the body of the ostrich, which it does.