Pelican - Behaviour and Ecology

Behaviour and Ecology

Pelicans swim well with their strong legs and their webbed feet. They rub the backs of their heads on their preen glands to pick up an oily secretion, which they transfer to their plumage to waterproof it. Holding their wings only loosely against their bodies, pelicans float with relatively little of their bodies below the water surface. They dissipate excess heat by gular flutter – rippling the skin of the throat and pouch with the bill open to promote evaporative cooling. They roost and loaf communally on beaches, sandbanks and in shallow water.

A fibrous layer deep in the breast muscles can hold the wings rigidly horizontal for gliding and soaring. 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 of up to 150 km (93 mi) 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. Hence substantial energy is saved while flying.

Adult pelicans rely on visual displays and behaviour to communicate, particularly using their wings and bills. Agonistic behaviour consists of thrusting and snapping at opponents with their bills, or lifting and waving their wings in a threatening manner. Adult pelicans grunt when at the colony, but are generally silent elsewhere or outside breeding season. Conversely, colonies are noisy as chicks vocalise extensively.