The wings are modified arms that, due to their structure and special shape, allow most birds to fly. Depending on the environment in which they live, birds have different types of wings. For example, penguins serve them as fins and ostriches use them for thermal regulation and courtship. This infographic from the Ábaco collection is part of The Art of Flying series, which also includes those originally titled: Why Do Birds Fly, The Secret of Success: Feathers, The Tail as a Rudder, So is Gliding Flight and So is Flapping Flight.