Several birds have lost the ability to fly, because flight is unnecessary for their way of life. Penguins and ostriches have very small wings and cannot fly. The penguin uses its wings in underwater ‘flight’, while the ostrich uses its wings only when displaying to other ostriches. The extinct dodo and the modern kiwi are examples of flightless birds. A rare kind of parrot has also lost the power of flight.

Picture credit: google