Pelicans (genus Pelecanus) are a genus of large that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before swallowing. They have predominantly pale plumage, except for the Brown pelican and . The bills, pouches, and bare facial skin of all pelicans become brightly coloured before the breeding season.
The eight living pelican species have a patchy, seasonally-dependent yet global distribution, ranging latitude from the tropics to the temperate zone. Pelicans are absent from interior Amazonian South America, from 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). They have also been seen hundreds of miles inland in North America, having flown northwards along the Mississippi River and other large waterways.
Long thought to be related to , , , and Sulidae, pelicans instead are most closely related to the shoebill and hamerkop storks (although these two birds are not actually true 'storks'), and are placed in the order Pelecaniformes. , , , and have been classified in the same order. Fossil evidence of pelicans dates back at least 36 million years to the remains of a tibiotarsus recovered from late Eocene strata of Egypt that bears striking similarity to modern species of pelican. They are thought to have evolved in the Old World and spread into the Americas; this is reflected in the relationships within the genus as the eight species divide into Old World and New World lineages. This hypothesis is supported by fossil evidence from the oldest pelican taxa.
Pelicans will frequent inland waterways but are most known for residing along maritime and coastal zones, where they feed principally on fish in their large throat pouches, diving into the water and catching them at/near the water's surface. They can adapt to varying degrees of water salinity, from freshwater and brackish to—most commonly—seawater. They are birds, travelling in flocks, hunting cooperatively, and breeding bird colony. Four white-plumaged species tend to nest on the ground, and four brown or grey-plumaged species nest mainly in trees. The relationship between pelicans and people has often been contentious. The birds have been persecuted because of their perceived competition with commercial and recreational fishing. Their populations have fallen through habitat destruction, disturbance, and environmental pollution, and three species are of conservation concern. They also have a long history of cultural significance in mythology, and in Christian and heraldry iconography.
Cladogram based on Hackett et al. (2008).
Later fossils from the Early Miocene found at Luberon, France, include Pelecanus sp. and Miopelecanus. Both fossils show a beak nearly morphologically identical to that of present-day pelicans. This remarkable stasis in pelican beak morphology may reflect strong functional constraints. Their specialized fish-eating beak has likely remained optimal over millions of years, with changes potentially reducing feeding efficiency. Some have also suggested that constraints imposed by flight may have limited the Skeleton of pelicans.
Notable fossil species (sorted by region and age) include:
Genetic analyses using mitochondrial and nuclear DNA have revealed a different picture of pelican relationships. These studies support the existence of two major clades: a New World clade, comprising the American white, brown, and Peruvian pelicans, and an Old World clade that includes the Dalmatian, pink-backed, spot-billed, Australian, and great white pelicans. This phylogeny suggests that pelicans evolved in the Old World and later colonized the Americas. Furthermore, it indicates that nesting behavior is more strongly influenced by body size than by genetic lineage.
Males are generally larger than females and have longer bills. The smallest species is the brown pelican, small individuals of which can be no more than and long, with a wingspan of as little as . The largest is believed to be the Dalmatian, at up to and in length, with a maximum wingspan of . The Australian pelican's bill may grow up to long in large males,
Pelicans have mainly light-coloured plumage, the exceptions being the brown and Peruvian pelicans. The bills, pouches, and bare facial skin of all species become brighter before breeding season commences. The throat pouch of the Californian subspecies of the brown pelican turns bright red, and fades to yellow after the eggs are laid, while the throat pouch of the Peruvian pelican turns blue. The American white pelican grows a prominent knob on its bill that is shed once females have laid eggs. The plumage of immature pelicans is darker than that of adults. Newly hatched chicks are naked and pink, darkening to grey or black after four to 14 days, then developing a covering of white or grey down feather.
A fibrous layer deep in the breast muscles can hold the wings rigidly horizontal for gliding and soaring. Thus, they use for soaring to heights of 3,000 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. 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.
The Australian pelican has two reproductive strategies depending on the local degree of environmental predictability. Colonies of tens or hundreds, rarely thousands, of birds breed regularly on small coastal and subcoastal islands where food is seasonally or permanently available. In arid inland Australia, especially in the endorheic Lake Eyre basin, pelicans breed opportunistically in very large numbers of up to 50,000 pairs, when irregular major floods, which may be many years apart, fill ephemeral and provide large amounts of food for several months before drying out again.
In all species, copulation takes place at the nest site; it begins shortly after pairing and continues for three to ten days before egg-laying. The male brings the nesting material, in ground-nesting species (which may not build a nest) sometimes in the pouch, and in tree-nesting species crosswise in the bill. The female then heaps the material up to form a simple structure.
The eggs are oval, white, and coarsely textured. All species normally lay at least two eggs; the usual clutch size is one to three, rarely up to six. Both sexes incubate with the eggs on top of or below the feet; they may display when changing shifts. Incubation takes 30–36 days; 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). Both parents feed their young. Small chicks are fed by regurgitation; after about a week, they are able to put their heads into their parents' pouches and feed themselves.
Parents of ground-nesting species sometimes drag older young around roughly by the head before feeding them. From about 25 days old, the young of these species gather in "pods" or "crèches" of up to 100 birds in which parents recognise and feed only their own offspring. By six to eight weeks, they wander around, occasionally swimming, and may practise communal feeding. Young of all species fledge ten to 12 weeks after hatching. They may remain with their parents afterwards, but are now seldom or never fed. They are mature at three or four years old. Overall breeding success is highly variable. Pelicans live for 15 to 25 years in the wild, although one reached an age of 54 years in captivity.
Large fish are caught with the bill-tip, then tossed up in the air to be caught and slid into the gullet head-first. A gull will sometimes stand on the pelican's head, peck it to distraction, and grab a fish from the open bill. Pelicans in their turn sometimes Kleptoparasitism from other waterbirds.
The brown pelican usually plunge-dives head-first for its prey, from a height as great as , especially for anchovy and menhaden. The only other pelican to feed using a similar technique is the Peruvian pelican, but its dives are typically from a lower height than the brown pelican. The Australian and American white pelicans may feed by low plunge-dives landing feet-first and then scooping up the prey with the beak, but they—as well as the remaining pelican species—primarily feed while swimming on the water. Aquatic prey is most commonly taken at or near the water surface. Although principally a fish eater, the Australian pelican is also an eclectic and opportunistic scavenger and carnivore that forages in landfill sites, as well as taking carrion
Pelicans may also eat birds. In southern Africa, eggs and chicks of the Cape cormorant are an important food source for great white pelicans. Several other bird species have been recorded in the diet of this pelican in South Africa, including Cape gannet chicks on Malgas Island as well as crowned cormorants, , greater crested terns, and on Dassen Island and elsewhere. The Australian pelican, which is particularly willing to take a wide range of prey items, has been recorded feeding on young Australian white ibis, and young and adult and . Brown pelicans have been reported preying on young in California and the eggs and nestlings of and nestling in Baja California, Mexico. Peruvian pelicans in Chile have been recorded feeding on nestlings of , juvenile Peruvian diving petrels, and . Cannibalism of chicks of their own species is known from the Australian, brown, and Peruvian pelicans. Non-native great white pelicans have been observed swallowing in St. James's Park in London, England.
The Peruvian pelican is listed as near threatened because, although the population is estimated by BirdLife International to exceed 500,000 mature individuals, and is possibly increasing, it has been much higher in the past. It declined dramatically during the 1998 El Niño event and could experience similar declines in the future. 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.
The spot-billed pelican has an estimated population between 13,000 and 18,000 and is considered to be near threatened in the IUCN Red List of Threatened Species. Numbers declined substantially during the 20th century, one crucial factor being the eradication of the important Sittaung River breeding colony in Burma through deforestation and the loss of feeding sites. The chief threats it faces are from habitat loss and human disturbance, but populations have mostly stabilised following increased protection in India and Cambodia.
The pink-backed pelican has a large population ranging over much of sub-Saharan Africa. In the absence of substantial threats or evidence of declines across its range, its conservation status is assessed as being of least concern. Regional threats include the drainage of wetlands and increasing disturbance in southern Africa. The species is susceptible to bioaccumulation of toxins and the destruction of nesting trees by logging.
The American white pelican has increased in numbers, with its population estimated at over 157,000 birds in 2005, becoming more numerous east of the continental divide, while declining in the west. However, whether its numbers have been affected by exposure to pesticides is unclear, as it has also lost habitat through wetland drainage and competition with recreational use of lakes and rivers.
Great white pelicans range over a large area of Africa and southern Asia. The overall trend in numbers is uncertain, with a mix of regional populations that are increasing, declining, stable, or unknown, but no evidence has been found of rapid overall decline, and the status of the species is assessed as being of least concern. Threats include the drainage of wetlands, persecution and sport hunting, disturbance at the breeding colonies, and contamination by pesticides and heavy metals.
The Dalmatian pelican has a population estimated at between 10,000 and 20,000 following massive declines in the 19th and 20th centuries. 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. It is listed as near threatened by the IUCN Red List of Threatened Species as the population trend is downwards, especially in Mongolia, where it is nearly extinct. However, several European colonies are increasing in size and the largest colony for the species, at the Small Prespa Lake in Greece, has reached about 1,400 breeding pairs following conservation measures.
Widespread across Australia, the Australian pelican has a population generally estimated at between 300,000 and 500,000 individuals. Overall population numbers fluctuate widely and erratically depending on wetland conditions and breeding success across the continent. The species is assessed as being of least concern.
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. More recently, such predation at South African seabird colonies has impacted on the conservation of threatened seabird populations, especially crowned cormorants, Cape cormorants, and . This has led to suggestions that pelican numbers should be controlled at vulnerable colonies.
Apart from habitat destruction and deliberate, targeted persecution, pelicans are vulnerable to disturbance at their breeding colonies by birdwatchers, photographers, and other curious visitors. 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.
In the late 1960s, following the major decline in brown pelican numbers in Louisiana from DDT poisoning, 500 pelicans were imported from Florida to augment and re-establish the population; over 300 subsequently died in April and May 1975 from poisoning by the pesticide endrin. About 14,000 pelicans, including 7,500 American white pelicans, perished from botulism after eating fish from the Salton Sea in 1990. In 1991, abnormal numbers of brown pelicans and Brandt's cormorants died at Santa Cruz, California, when their food fish (anchovies) were contaminated with neurotoxin domoic acid, produced by the diatom Pseudo-nitzschia.
As waterbirds that feed on fish, pelicans are highly susceptible to , both directly by being oiled and by the impact on their food resources. A 2007 report to the California Fish and Game Commission estimated that during the previous 20 years, some 500–1,000 brown pelicans had been affected by oil spills in California. A 2011 report by the Center for Biological Diversity, a year after the April 2010 Deepwater Horizon oil spill, said that 932 brown pelicans had been collected after being affected by oiling and estimated that ten times that number had been harmed as a result of the spill.
Where pelicans interact with fishers, through either sharing the same waters or scavenging for fishing refuse, they are especially vulnerable to being hooked and entangled in both active and discarded fishing lines. are swallowed or catch in the skin of the pouch or webbed feet, and strong monofilament fishing line can become wound around bill, wings, or legs, resulting in crippling, starvation, and often death. Local rescue organisations have been established in North America and Australia by volunteers to treat and rehabilitate injured pelicans and other wildlife.
The brown pelican has a similarly extensive range of parasites. The nematodes Contracaecum multipapillatum and C. mexicanum and the trematode Ribeiroia ondatrae have caused illness and mortality in the Puerto Rico population, possibly endangering the pelican on this island.
Many pelican parasites are found in other bird groups, but several louse are very host-specific. Healthy pelicans can usually cope with their lice, but sick birds may carry hundreds of individuals, which hastens a sick bird's demise. The pouch louse Piagetiella peralis occurs in the pouch and so it cannot be removed by preening. While this is usually not a serious problem even when present in such numbers that it covers the whole interior of the pouch, sometimes inflammation and bleeding may occur from it and harm the host.
In May 2012, hundreds of Peruvian pelicans were reported to have perished in Peru from a combination of starvation and roundworm infestation.
In Kashrut, pelican is not considered kosher (fit for consumption), as it is a type of seabird and therefore considered an unclean animal.
An origin myth from the Murri people of Queensland, cited by Andrew Lang, describes how the Australian pelican acquired its black and white plumage. The story tells that the pelican was once a black bird. During a flood, he made a canoe to save drowning people. He fell in love with a woman and decided to save her, but she and her friends tricked him and escaped. The pelican consequently began preparing to go to war against them by daubing himself with white clay as war paint. Before he had finished, another pelican, on seeing such a strange piebald creature, killed him with its beak, and all such pelicans have been black and white ever since.
The Moche culture people of ancient Peru worshipped nature.Benson, Elizabeth (1972) The Mochica: A Culture of Peru New York: Praeger Press. They placed emphasis on animals and often depicted pelicans in their art.
The self-sacrificial characterization of the pelican was reinforced by widely read medieval bestiary. The device of "a pelican in her piety" or "a pelican vulning (from Latin , "I wound, I injure, I hurt") herself" was used in religious iconography and heraldry.
The legends of self-wounding and the provision of blood occur across cultures. For example, an Indian folktale depicts a pelican that killed her young by rough treatment, but was then so contrite that she Resurrection them with her own blood. Such legends may have arisen because of the impression a pelican sometimes gives that it is stabbing itself with its bill. In reality, it often presses this onto its chest to fully empty the pouch. 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.
The pelican is featured in many Christian artworks, especially in Europe. For example, the first (1611) edition of the King James Bible contains a depiction of a pelican feeding her young in an oval panel at the bottom of the title page. The "pelican in her piety" appears in the 1686 reredos by Grinling Gibbons in the church of St Mary Abchurch in the City of London. Earlier medieval examples of the motif appear in painted murals, for example, the mural in the parish church of Belchamp Walter, Essex (c. 1350).
The image became also linked to the medieval religious feast of Corpus Christi. The universities of Oxford and Cambridge each have colleges named for the religious festival nearest the dates of their establishment, and both Corpus Christi College, Cambridge, and Corpus Christi College, Oxford, feature pelicans on their coats of arms.
Commercially, the pelican has been adopted as a corporate symbol in banking, publishing, and healthcare. A white pelican logo is used by the Portuguese bank Montepio Geral, The name and image were also employed by Pelican Books, an imprint of nonfiction titles published by Penguin Books. In the context of blood donation, where the pelican's symbolism of self-giving is especially resonant, the Irish Blood Transfusion Service features a pelican in its logo and operated for many years from Pelican House in Dublin. Similarly, Sanquin, the nonprofit organization responsible for blood supply in the Netherlands, uses a stylized pelican in its logo, continuing this humanitarian association.|left]] coin.|left]]
Alcatraz Island was given its name by the Spanish because of the large numbers of nesting there. The word alcatraz is itself derived from the Arabic al-caduos, a term used for a water-carrying vessel and likened to the pouch of the pelican. The English name albatross is also derived by corruption of the Spanish word.
Taxonomy and systematics
Etymology
Taxonomy history
Order and related taxa
Phylogenetic relationships
|style="vertical-align:top;"
Evolution and fossil record
Controversial and dubious fossil assignments
Extant species and phylogeny
Species overview
List of living species
American white pelican
Pelecanus erythrorhynchos
Gmelin, 1789 Length , wingspan , weight . Plumage almost entirely white, except for black primary and secondary remiges only visible in flight. Monotypic taxon. Breeds in inland Canada and United States, wintering in southern United States, Mexico and Central America.Elliott (1992), p. 310 Status: least concern. Brown pelican
Pelecanus occidentalis
Linnaeus, 1766 Length up to , wingspan , weight . Smallest pelican; distinguished by brown plumage; feeds by plunge-diving. Five subspecies. Coastal distribution ranging from North America and the Caribbean to northern South America and the Galapagos. Status: least concern. Peruvian pelican
Pelecanus thagus
Molina, 1782 Length up to , wingspan , average weight . Dark with a white stripe from the crown down the sides of the neck. Monotypic. Pacific Coast of South America from Ecuador and Peru south through to southern Chile. Status: near threatened. Great white pelican
Pelecanus onocrotalus
Carl Linnaeus, 1758 Length , wingspan , weight . Monotypic. Patchy distribution from eastern Mediterranean east to Indochina and Malay Peninsula, and south to South Africa. Status: least concern. Australian pelican
Pelecanus conspicillatus
Temminck, 1824 Length , wingspan , weight . Predominantly white with black along primaries and very large, pale pink bill. Monotypic. Australia and New Guinea; vagrant to New Zealand, Solomons, Bismarck Archipelago, Fiji and Wallacea. Status: least concern. Pink-backed pelican
Pelecanus rufescens
Gmelin, 1789 Length , wingspan , weight .Elliott (1992), p. 309 Grey and white plumage, occasionally pinkish on the back, with a yellow upper mandible and grey pouch. Monotypic. Africa, Seychelles and southwestern Arabia; extinct in Madagascar. Status: least concern. Dalmatian pelican
Pelecanus crispus
Bruch, 1832 Length , wingspan , weight . Largest pelican; differs from great white pelican in having curly nape feathers, grey legs and greyish-white plumage. Monotypic. South-eastern Europe to India and China. Status: near threatened. Spot-billed pelican
Pelecanus philippensis
Gmelin, 1789 Length , wingspan , weight c. . Mainly grey-white all over, with a grey hindneck crest in breeding season, pinkish rump and spotted bill pouch. Monotypic. Southern Asia from southern Pakistan across India east to Indonesia; extinct in the Philippines and possibly eastern China. Status: near threatened.
Description
Air sacs
Distribution and habitat
Behaviour and ecology
Breeding and lifespan
Feeding
Status and conservation
Populations
Culling and disturbance
Poisoning and pollution
Parasites and disease
Symbolism and cultural significance
Ancient and indigenous beliefs
Christian symbolism
Myth of self-sacrifice
Religious art and literature
Elizabeth I and the Church
Heraldry and symbolism
Heraldic imagery
Public symbols
Emblems and logos in institutions
Educational institutions
Sports teams
Commercial and nonprofit organizations
National and regional symbols
Namesakes in nature
Literature and humor
Notes
Cited texts
External links
|
|