Feathers play a very important role in communication between many different species of birds. Some birds communicate with each other mostly by sound, such as warblers in nightingales. These often look very drab and dull, because they do not need the brightly coloured feathers that are involved in visual forms of communication.
Other birds, particularly those living noisy places, depend on their appearance to attract potential mates. Good courtship displays depend on very highly coloured feathers and complex displays involving movement and posturing of the wings and the feathers. Humming birds, birds of paradise and peacocks are among the most brightly coloured birds that gives the best displays.
Colouring on feathers can also give the bird camouflage. Some birds have mottled plumage and can merge into the background of different habitats. As well as being used mating displays, feathers and wings are also flapped vigorously to scare off potential predators or other birds competing for breeding positions.