 Thus, they use thermals for soaring to heights of 3000 m (10,000 ft) or more, combined both with gliding and with flapping flight in V formation, to commute distances up to to feeding areas.Pelicans also fly low (or "skim") over stretches of water, using a phenomenon known as ground effect to reduce drag and increase lift.As the air flows between the wings and the water surface, it is compressed to a higher density and exerts a stronger upward force against the bird above.