A pelican, derived from the Greek word πελεκυς pelekys (meaning “axe” and applied to birds that cut wood with their bills or beaks) is a large water bird with a large throat pouch, belonging to the bird family Pelecanidae.
Along with the darters, cormorants, gannets, boobies, frigatebirds, and tropicbirds, pelicans make up the order Pelecaniformes. Modern pelicans, of which there are eight species, are found on all continents except Antarctica. They primarily inhabit warm regions, though breeding ranges reach 45° south (Australian Pelican, P. conspicillatus) and 60° North (American White Pelicans, P. erythrorhynchos, in western Canada). Birds of inland and coastal waters, they are absent from polar regions, the deep ocean, oceanic islands, and inland South America.
Pelicans are large birds with large pouched bills. The smallest is the Brown Pelican (P. occidentalis), small individuals of which can be as little as 2.75 kg (6 lb), 106 cm (42 in) long and can have a wingspan of as little as 1.83 m (6 ft). The largest is believed to be the Dalmatian Pelican (P. crispus), at up to 15 kg (33 lb), 183 cm (72 in) long, with a maximum wingspan of 3 meters (nearly 10 foot). The Australian Pelican has the longest bill of any bird.
Pelicans swim well with their short, strong legs and their feet with all four toes webbed (as in all birds placed in the order Pelecaniformes). The tail is short and square, with 20 to 24 feathers. The wings are long and have the unusually large number of 30 to 35 secondary flight feathers. A layer of special fibers deep in the breast muscles can hold the wings rigidly horizontal for gliding and soaring. Thus they can exploit thermals to commute over 150 km (100 miles) to feeding areas.
The pelicans can be divided into two groups: those with mostly white adult plumage, which nest on the ground (Australian, Dalmatian, Great White, and American White Pelicans), and those with gray or brown plumage, which nest in trees (Pink-backed, Spot-billed, and Brown, plus the Peruvian Pelican, which nests on sea rocks). The Peruvian Pelican is sometimes considered conspecific with the Brown Pelican.
The diet of a Pelican usually consists of fish, but they also eat amphibians, crustaceans and on some occasions, smaller birds. They often catch fish by expanding the throat pouch. Then they must drain the pouch above the surface before they can swallow. This operation takes up to a minute, during which time other seabirds are particularly likely to steal the fish. Pelicans in their turn sometimes pirate prey from other seabirds.
The white pelicans often fish alone. They will form a line to chase schools of small fish into shallow water, and then scoop them up. Large fish are caught with the bill-tip, then tossed up in the air to be caught and slid into the gullet head first.
The Brown Pelican of North America usually plunge-dives for its prey. Rarely, other species such as the Peruvian Pelican and the Australian Pelican practice this method.
Consumption of other birds is rare. In 2006, a pelican swallowed a living pigeon in St. James Park, London. According to tourists watching it, the pelican walked to the pigeon and grabbed it in its beak, hence starting the 20 minute struggle which ended when the victim was swallowed “head first down while flapping all the way down”. A pelican in Zoo Basel has been known to eat ducks. It has been suggested this feeding behaviour is more likely with captive birds that live in a semi-urban environment and are in constant close contact with humans, although it has been observed in the wild.
On the island of Malgas in South Africa, the biologist Marta de Ponte was the first to record Great White Pelicans eating Cape Gannet chicks. The pelicans were then captured on film exhibiting this behaviour in the BBC documentary Life (BBC TV series). The same species of pelican has been observed swallowing Cape cormorants, kelp gulls, swift terns and African penguins
Pelicans are gregarious and nest colonially. The ground-nesting (white) species have a complex communal courtship involving a group of males chasing a single female in the air, on land, or in the water while pointing, gaping, and thrusting their bills at each other. They can finish the process in a day. The tree-nesting species have a simpler process in which perched males advertise for females.
In all species copulation begins shortly after pairing and continues for 3 to 10 days before egg-laying. The male brings the nesting material, ground-nesters (which may not build a nest) sometimes in the pouch and tree-nesters crosswise in the bill. The female then heaps the material up to form a simple structure.
Both sexes incubate with the eggs on top of or below the feet. They may display when changing shifts. All species lay at least two eggs, and hatching success for undisturbed pairs can be as high as 95 percent, but because of competition between siblings or outright siblicide, usually all but one nestling dies within the first few weeks (or later in the Pink-backed and Spot-billed species). The young are fed copiously. Before or especially after being fed, they may seem to have a seizure that ends in falling unconscious; the reason is not clearly known.
Parents of ground-nesting species have another strange behavior: they sometimes drag older young around roughly by the head before feeding them. The young of these species gather in “pods” or “crèches” of up to 100 birds in which parents recognize and feed only their own offspring. By 6 to 8 weeks they wander around, occasionally swimming, and may practice communal feeding.
Young of all species fledge 10 to 12 weeks after hatching. They may remain with their parents afterwards, but are now seldom or never fed. Overall breeding success is highly inconsistent.
Pairs are monogamous for a single season, but the pair bond extends only to the nesting area; mates are independent away from the nest.
The Dalmatian Pelican and the Spot-billed Pelican are the rarest species, with the population of the former estimated at between 10,000 and 20,000 and that of the latter at 13,000 to 18,000. The most common is believed to be the Australian Pelican, with a population generally estimated at around 400,000 individuals. However, estimates for the species have varied wildly between 100,000 and 1,000,000 over the years, and it is possible that the White Pelican, the population of which is more consistently estimated at 270,000 and 290,000 individuals, is in fact the more common species. The brown pelican may be even more numerous with estimates of 650,000 birds throughout its range. It has been removed from the endangered species list.
In medieval Europe, the pelican was thought to be particularly attentive to her young, to the point of providing her own blood when no other food was available. As a result, the pelican became a symbol of the Passion of Jesus and of the Eucharist (see for example the hymn “Adoro te devote“, or “Humbly We Adore Thee”, by Saint Thomas Aquinas, where in the second to last verse he makes reference to Christ, the loving divine pelican). It also became a symbol in bestiaries for self-sacrifice, and was used in heraldry (“a pelican in her piety” or “a pelican vulning (wounding) herself”). Another version of this is that the pelican used to kill its young and then resurrect them with its blood, this being analogous to the sacrifice of Jesus. Thus the symbol of the Irish Blood Transfusion Service (IBTS) is a pelican, and for most of its existence the headquarters of the service was located at Pelican House in Dublin, Ireland.
The emblems of both Corpus Christi College, Cambridge, Corpus Christi College, Oxford and the medical faculties of Charles University in Prague are pelicans, showing its use as a medieval Christian symbol (‘Corpus Christi’ means ‘body of Christ’).
These legends may have arisen because pelicans look as if they are stabbing themselves as they often press their bill into their chest to fully empty their pouch. Other possibilities are that they often rest their bills on their breasts, and that the Dalmatian Pelican has a blood-red pouch in the early breeding season.
The symbol is used today as the national bird of Sint Maarten and features on its coat of arms. It is also used on the Louisiana state flag and Louisiana state seal, as the Brown pelican is the Louisiana state bird. The pelican is featured prominently on the seals of Loomis Chaffee, Louisiana State University, and Tulane University, and is also the mascot of Tulane. A pelican logo is used by the Portuguese bank Montepio Geral.
The pelican has also been the subject of a poem by John Bennet and subsequent song—The Pelican—by Richard Proulx, composed in 1995. The song was dedicated to the Cathedral Choir of the Cathedral of the Madeleine, Salt Lake City, Utah.
Several news magazines such as Time and the Economist, and environmental groups, have used the oil-drenched pelican as a symbol of the environmental impact of the Deepwater Horizon oil spill.
Source : www.wikipedia.org