Pelicans are absent from interior Amazonian South America, from polar regions and the open ocean; at least one species is known to migrate to the inland desert of Australia's Red Centre, after heavy rains create temporary lakes.

White pelicans are also observed at the American state of Utah's Great Salt Lake, for example, some 600 miles (965 km) from the nearest coastline (the Pacific West Coast).

[14] The oldest known record of Pelicans is a right tibiotarsus very similar to those of modern species from the Birket Qarun Formation in the Wadi El Hitan in Egypt, dating to the late Eocene (Priabonian), referred to the genus Eopelecanus.

[1] P. rufescens P. philippensis P. crispus P. conspicillatus P. onocrotalus P. occidentalis P. thagus P. erythrorhynchos Suliformes Herons (Ardeidae) Ibises and spoonbills (Threskiornithidae) Hamerkop (Scopus umbretta) Shoebill (Balaeniceps rex) Pelicans (Pelecanus) Cladogram based on Hackett et al.

The largely marine brown and Peruvian pelicans, formerly considered conspecific,[4] are sometimes separated from the others by placement in the subgenus Leptopelecanus[15] but in fact species with both sorts of appearance and nesting behavior are found in either.

[39] An Early Miocene fossil has been named Miopelecanus gracilis on the basis of certain features originally considered unique, but later thought to lie within the range of interspecific variation in Pelecanus.

[42] Several Pelecanus species have been described from fossil material, including:[43] Pelicans are very large birds with very long bills characterised by a downcurved hook at the end of the upper mandible, and the attachment of a huge gular pouch to the lower.

Although they are among the heaviest of flying birds,[51] they are relatively light for their apparent bulk because of air pockets in the skeleton and beneath the skin, enabling them to float high in the water.

Thus, they use thermals for soaring to heights of 3,000 m (10,000 ft) or more,[61] combined both with gliding and with flapping flight in V formation, to commute distances up to 150 km (93 mi) to feeding areas.

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.

[4] The location of the breeding colony is constrained by the availability of an ample supply of fish to eat, although pelicans can use thermals to soar and commute for hundreds of kilometres daily to fetch food.

Colonies of tens or hundreds, rarely thousands, of birds breed regularly on small coastal and subcoastal islands where food is seasonally or permanently available.

Incubation takes 30–36 days;[15] hatching success for undisturbed pairs can be as high as 95%, but because of sibling competition or siblicide, in the wild, usually all but one nestling dies within the first few weeks (later in the pink-backed and spot-billed species).

Nearer the shore, several encircle schools of small fish or form a line to drive them into the shallows, beating their wings on the water surface and then scooping up the prey.

Conservation needs include regular monitoring throughout the range to determine population trends, particularly after El Niño years, restricting human access to important breeding colonies, and assessing interactions with fisheries.

Numbers declined substantially during the 20th century, one crucial factor being the eradication of the important Sittaung valley breeding colony in Burma through deforestation and the loss of feeding sites.

The main ongoing threats include hunting, especially in eastern Asia, disturbance, coastal development, collision with overhead power lines, and the over-exploitation of fish stocks.

[5] Starting in the 1880s, American white pelicans were clubbed and shot, their eggs and young were deliberately destroyed, and their feeding and nesting sites were degraded by water management schemes and wetland drainage.

[95] Great white pelicans on Dyer Island, in the Western Cape region of South Africa, were culled during the 19th century because their predation of the eggs and chicks of guano-producing seabirds was seen to threaten the livelihood of the guano collectors.

Human presence alone can cause the birds to accidentally displace or destroy their eggs, leave hatchlings exposed to predators and adverse weather, or even abandon their colonies completely.

[5] In 1991, abnormal numbers of brown pelicans and Brandt's cormorants died at Santa Cruz, California, when their food fish (anchovies) were contaminated with neurotoxic domoic acid, produced by the diatom Pseudo-nitzschia.

The nematodes Contracaecum multipapillatum and C. mexicanum and the trematode Ribeiroia ondatrae have caused illness and mortality in the Puerto Rican population, possibly endangering the pelican on this island.

[111][112] An origin myth from the Murri people of Queensland, cited by Andrew Lang, describes how the Australian pelican acquired its black and white plumage.

[118] The Physiologus explains this as mirroring the pain inflicted on God by people's idolatry, and the self-sacrifice of Jesus on the cross which redeems the sinful (see the blood and water gushing from the wound in his side).

[118] This text was widely copied, translated, and sometimes closely paraphrased during the Middle Ages, for instance by 13th-century authors Guillaume le Clerc and Bartholomaeus Anglicus.

[118] In a newer, also medieval version of the European myth, the pelican was thought to be particularly attentive to her young, to the point of providing them with blood by wounding her own breast when no other food was available.

[121] This mythical characteristic is referenced in the hymn "Adoro te devote" ("Humbly We Adore Thee"), where in the penultimate verse, Saint Thomas Aquinas describes Christ as the loving divine pelican, one drop of whose blood can save the world.

Another possible derivation is the tendency of the bird to rest with its bill on its breast; the Dalmatian pelican has a blood-red pouch in the early breeding season and this may have contributed to the myth.

[127] The King of Portugal John II adopted the pelican as is own personal sygil while he was Infante, evoking the Christian symbology to equate the sacrifice of his blood to feed the nation.

[142] The original version ran:[143] A wonderful bird is the pelican, His bill will hold more than his belican, He can take in his beak Food enough for a week, But I'm damned if I see how the helican.