American white pelicans are found throughout North America. They breed in inland, prairie regions of the United States and Canada and winter in southern and coastal areas. Breeding occurs in suitable habitat from British Columbia, Alberta, Saskatchewan, Manitoba, and southwestern Ontario south through northern California, Nevada, and Colorado. They winter in southern California, coastal and eastern Mexico, the coastal plain of Texas, and throughout the Gulf states, including Florida. Populations that breed mostly east of the continental divide tend to migrate to winter ranges in the Gulf of Mexico, breeding populations west of the continental divide tend to migrate towards Baja California and western Mexico. There are several, small year-round populations along the Gulf of Mexico and in central Durango, Mexico. The winter range is characterized by minimum January temperatures above 4 degrees Celsius.
Biogeographic Regions: nearctic (Native )
- Knopf, F., R. Evans. 2004. American White Pelican (Pelecanus erythrorhynchos). The Birds of North America Online, 57: 1-20. Accessed May 06, 2009 at http://bna.birds.cornell.edu/bna/species/057.
Regularity: Regularly occurring
Type of Residency: Breeding
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) Nesting occurs locally in south-central British Columbia, Alberta, Saskatchewan, Manitoba, and southwestern Ontario south through northern California, Nevada, Utah, Colorado, South Dakota, and Minnesota; also on the central coast of Texas and sporadically in east-central Mexico (Tamaulipas) and central Durango, Mexico (Johnsgard 1993, Knopf and Evans 2004). During the nonbreeding season the range includes Florida, Gulf of Mexico coast south to northern Yucatan Peninsula, and central California south to southern Baja California and through western mainland Mexico to Nicaragua (AOU 1983, Knopf and Evans 2004). In North America, the highest winter density occurs in southern Texas (Root 1988); other important areas include the Gulf coast and Everglades region of Florida. In summer, white pelicans sometimes wander north of the usual range.
Coded range extent refers to breeding range.
American white pelicans are large, white pelicans, there are no similar species in North America. Their primary and outer secondary feathers are black, their bill and gular pouch are flesh colored or yellow, and their legs are pale yellow to bright orange. They have a flattened protuberance on the upper bill. American white pelicans are from 127 to 165 cm in length. The other North American pelican species, brown pelicans, are smaller, with dark plumage. Males are slightly larger than females. Their wingspan is from 244 to 290 and reported masses are from 4.54 to 9 kg. There are no described subspecies or geographic variation.
Range mass: 4.54 to 9 kg.
Range length: 127 to 165 cm.
Range wingspan: 244 to 290 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Length: 158 cm
Weight: 7500 grams
Catalog Number: USNM 84752
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Birds
Sex/Stage: Male; Adult
Preparation: Skin: Whole
Collector(s): R. Ridgway
Year Collected: 1868
Locality: Pyramid Lake, Washoe, Nevada, United States, North America
- Type: Ridgway. August 8, 1874. American Sportsman. 4: 297 (text-figs.).
American white pelicans winter in coastal areas, such as coastal bays and estuaries. Significant inland wintering areas are the Salton Sea in California and large rivers in areas where water flow prevents freezing. They breed on islands in or near shallow, inland lakes, rivers, and marshes. Islands can be either permanent islands in freshwater water bodies or temporary islands in wetlands. These temporary nesting and roosting habitats can be important in determining breeding and winter distribution. Breeding islands are commonly more than 50 km from areas used for foraging. American white pelicans migrate over inland areas with large lakes and rivers for resting and foraging.
Habitat Regions: temperate ; tropical ; saltwater or marine ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water
Other Habitat Features: estuarine
Habitat and Ecology
Comments: Habitat includes rivers, lakes, reservoirs, estuaries, bays, and open marshes, sometimes inshore marine habitats. Pelicans rest/roost on islands and peninsulas. Nests usually are on islands or peninsulas (natural or dredge spoils) in brackish or freshwater lakes, or on ephemeral islands in shallower wetlands as in the northern Great Plains or on the Texas coast (knopf and Evans 2004). Eggs are laid on the ground in a slight depression or on a mound of earth and debris 24-36 inches across, 15-20 inches high (Terres 1980), usually on low flat, or gently sloping terrain. Nest sites usually are in open areas but often near vegetation, driftwood, or large rocks (Spendelow and Patton 1988). Habitats used in winter are mainly coastal but also include also inland waters such as the Salton Sea and some rivers with open water (Knopf and Evans 2004). Suitable sand bars and similar sites for roosting or loafing are important components of winter habitat (Knopf and Evans 2004).
Water temperature and chemistry ranges based on 1 sample.
Depth range (m): 0 - 0
Temperature range (°C): 16.316 - 16.316
Nitrate (umol/L): 0.240 - 0.240
Salinity (PPS): 33.496 - 33.496
Oxygen (ml/l): 5.685 - 5.685
Phosphate (umol/l): 0.330 - 0.330
Silicate (umol/l): 1.436 - 1.436
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Most are long-distance migrants; resident along Gulf coast of Texas and Tamaulipas (Johnsgard 1993). Migration corridors are mostly inland. Winter range of breeders from North Dakota and Saskatchewan includes the western Gulf coast; some birds from Saskatchewan have been recovered on the Pacific coast of Mexico and El Salvador; most breeders from western Wyoming, Utah, Nevada, and British Columbia winter in California and western Mexico (see Johnsgard 1993).
Maximum distance between nesting site and breeding season foraging area can be 100 to 300 kilometers (Low et al. 1950, Marshall and Giles 1953, Lingle and Sloan 1980; also see Johnsgard 1993).
American white pelicans forage in shallow waters for fish, crustaceans, and amphibians. They may also forage in deeper waters where fish occur near the surface. They forage during the day typically, but may forage at night during the breeding season. They forage alone or in cooperative groups, they dip their bills into the water while swimming at the surface and scoop prey into their bill and gular pouch. Cooperative foraging groups may collaborate to drive prey into shallow waters to make it more difficult for them to escape capture. Individuals that forage in groups tend to have greater foraging success. Plunge-diving, as in brown pelicans, has only been rarely observed in these pelicans. They will also take prey from other pelicans or waterbirds, including double-crested cormorants, gulls, and other pelicans. American white pelicans eat mainly small, schooling fish, although they also eat crayfish and amphibians on inland lakes and rivers in the breeding season. Fish recorded in the diet include carp, minnows, tui chub, and occasionally game fish, such as salmon.
Animal Foods: amphibians; fish; aquatic crustaceans
Primary Diet: carnivore (Piscivore )
Comments: Diet includes mainly fishes of little commercial value (e.g., carp, perch, catfish, suckers, sticklebacks, minnows) (Terres 1980), also locally trout, centrarchids, tiger salamanders, or crayfishes. Locally, tiger salamanders may be important as food for chicks. Foraging often occurs in shallow water. Pelicans sometimes forage cooperatively, forming a semicircle and herding fishes.
American white pelicans often breed in colonies along with double-crested cormorants, gull species, Canada geese, great blue herons, common terns, and Caspian terns.
American white pelicans suffer from infestations of biting lice (Piagetiella peralis), especially around their mouth and gular pouch. Nematodes (Contracaecum spiculigerum) and tape worms (tape worms Hymenolepis species, Dibothrium cordiceps, Oilgorchis longivaginatus) have been reported from guts. One individual was infested with subcutaneous mites (Pelecanectes apunctatus).
- biting lice (Piagetiella peralis)
- nematodes (Contracaecum spiculigerum)
- tape worms (Hymenolepis species)
- tape worms (Dibothrium cordiceps)
- tape worms (Oilgorchis longivaginatus)
- subcutaneous mites (Pelecanectes apunctatus)
Breeding colonies on isolated islands help to lessen the threat of terrestrial predators on American white pelican young and eggs. Red foxes and coyotes are threats to breeding colonies that are accessible. Gull species prey on eggs and young, including herring gulls, California gulls, and ring-billed gulls. Also, common ravens prey on eggs and great horned owls and bald eagles take young. Adult size may lessen the risk of predation, but coyotes have been known to take adults. Although American white pelicans readily forage and loaf near humans, they are easily disturbed from nests, abandoning their young readily when a threat is perceived. Gulls take advantage of this to attack exposed nestlings. They also attack nestlings that have wandered from the nest or been expelled by an older sibling. Gulls also take food from young if they empty their stomach contents after being disturbed. These pelicans don't leave the nest in response to avian predators, instead jabbing at them with their bills.
- red foxes (Vulpes vulpes)
- coyotes (Canis latrans)
- herring gulls (Larus argentatus)
- California gulls (Larus californicus)
- ring-billed gulls (Larus delawarensis)
- common ravens (Corvus corax)
- great horned owls (Bubo virginianus)
- bald eagles (Haliaeetus leucocephalus)
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 - 80
Comments: Breeding occurrences include at least 27 colonies east of the Continental Divide and 15 west of the Divide; several additional colonies likely exist but have not been recently documented (King and Anderson 2005).
100,000 - 1,000,000 individuals
Comments: Using available data (1998-2001), King and Anderson (2005) determined that at least 27 American white pelican colonies and 48,240 nests occur east of the Continental Divide and at least 15 colonies and 18,790 nests exist west of the Divide, for a total of about 134,000 breeding pelicans in North America. However, many pelican colonies have not been surveyed since the early 1980s, and these figures do not include several colonies in Canada, the United States, and Mexico. Population size in 1995, including nonbreeders, was estimated at 400,000 (Keith 2005). The largest colony (34,000 breeders in 2002) is at Chase Lake, North Dakota (Sovoda et al. 2005).
Gregarious. Significant predators at various breeding sites include gulls, coyotes, and probably large corvids and other mammals.
Life History and Behavior
Adult American white pelicans are relatively silent, only using low grunts when in aggressive or sexual interactions. Young pelicans squawk loudly to beg for food. American white pelicans use a variety of visual displays to communicate aggression, appeasement, and alarm. They will jab at others with their bill or extend their gaped mouth towards them, usually in aggressive interactions around territories or mating. They hold their head upright with the bill extended horizontally and the gular pouch expanded, accompanied by a grunt, as a greeting or mild threat. In flight over colonies they stop flapping briefly and hold the bill down as another mild threat. Crouching or bowing is an appeasement display in young and adults. Courtship includes several visual displays in the air and on the ground, including circular courtship flights above the colony, parallel strutting displays between pairs, bowing, and head swaying between mates at the nest.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Comments: Feeding activity generally peaks in morning and late afternoon or evening. In some areas, foraging occurs at night as well as diurnally (McMahon and Evans 1992).
American white pelicans typically successfully raise just 1 of the 2 eggs they lay. Only 9.7% of clutches in one colony successfully raised 2 young to fledgling. Average mortality of that offspring through its first year of life is 41%. Average mortality from the 1st to 2nd year is 16%, and average mortality drops after that. The oldest recorded American white pelican in the wild was 26.4 years old. Nestlings and eggs die as a result of rolling out of nests, nest abandonment, starvation, attacks by other pelicans in the nesting colony, exposure, and predation. Adults are killed by severe weather, hitting wires, and diseases such as botulism.
Status: wild: 26.4 (high) years.
Lifespan, longevity, and ageing
American white pelicans form monogamous pairs in breeding season and defend small nesting territories in breeding colonies. Pair bonds form on arrival at the breeding colony through courtship rituals. These courtship displays include a circular courtship flight, parallel strutting walks, head swaying, and bowing. Bonds last through most of the breeding season, but whether pairs reform in subsequent years is unknown. Males guard female mates, although extra-pair copulations seem rare.
Mating System: monogamous
Once the bulk of birds arrive on the breeding grounds, pairs begin to form and breed. Mating occurs from late March through early May. Once a pair has formed, they begin to establish and defend a nest scrape. This process is highly synchronous in colonies, with nests being established over the course of about a week. Nests are simple scrapes with low rims on bare, level ground that are accessible to flying pelicans. Nest sites typically have little vegetation, but may be among low shrubs, weeds, or grass. They have 1 brood each year, laying 2 chalky-white eggs 2 days apart. If an egg is lost, it is not replaced. If both are lost, the nest is deserted. Eggs are incubated continuously under the foot webs of parents for about 30 days and brooded for about 17 days further. Young are fed by regurgitation by parents until the young leaves the colony at fledging, usually at 10 to 11 weeks after hatching. American white pelicans begin breeding at 3 years old.
Breeding interval: American white pelicans breed once yearly.
Breeding season: Breeding occurs from late March through early May.
Range eggs per season: 1 to 2.
Average eggs per season: 2.
Average time to hatching: 30 days.
Range fledging age: 10 to 11 weeks.
Average time to independence: 3 years.
Average age at sexual or reproductive maturity (female): 3 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Both parents incubate eggs, taking turns every 72 hours. When brooding, parents exchange places about every day.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Protecting: Male, Female)
- Knopf, F., R. Evans. 2004. American White Pelican (Pelecanus erythrorhynchos). The Birds of North America Online, 57: 1-20. Accessed May 06, 2009 at http://bna.birds.cornell.edu/bna/species/057.
Egg laying occurs May-July in Texas, late April-June (mainly before June) in Utah. In Canada, nesting begins in May or June; hatching in the first nests sometimes precedes initiation of the last clutches. In Manitoba, flocks first flew over colony sites 34-38 days before hatching. Clutch size is commonly 2, but pairs rarely fledge more than one young. Incubation, by both adults, averages 31-32 days, Young are tended by adults, leave nest in about 21-28 days, join other young in group, fledge at 9-10 weeks, and attain sexual maturity usually at 3 years. Mortality of eggs and chicks generally is high. Female generally does not renest following clutch loss.
Molecular Biology and Genetics
Barcode data: Pelecanus erythrorhynchos
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Pelecanus erythrorhynchos
Public Records: 4
Specimens with Barcodes: 6
Species With Barcodes: 1
There have been documented increases in American white pelican populations in recent years, resulting from conservation efforts. Historically populations declined in response to destruction of breeding and foraging habitats and continued destruction of wetland habitats remains one of the most important influences on current populations. American white pelicans are especially sensitive to human disturbance at nesting sites, where human presence can result in temporary or permanent nest abandonment, increasing the likelihood of mortality associated with exposure and gull predation. Common human disturbances at nesting colonies are low-flying airplanes or motorboats. Pesticide use throughout their range has resulted in egg-shell thinning and poisoning. They are considered least concern by the IUCN because of their large population sizes and broad range.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N3B - Vulnerable
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Reasons: Large nesting and winter range in Canada, United States, and Mexico; several dozen colonies include more than 60,000 nesting pairs; population has increased greatly since the 1960s; highly vulnerable to disturbance; habitat protection remains a concern, as does increased incidence and severity of disease.
Global Short Term Trend: Increase of 10 to >25%
Comments: The number of nesting pairs in 20 colonies that were surveyed during 1979-81 and again in 1998-2001 more than doubled during that approximately 20-year time interval (King and Anderson 2005).
Breeding Bird Survey data indicate that the continental population increasied steadily and rapidly at rate of 3.9 percent per year from 1980 through 2003 (Knopf and Evans 2004).
Global Long Term Trend: Decline of 30-70%
Comments: Severe declines occurred historically (King and Anderson 2005, Murphy 2005), but the magnitude of the difference between the former population size and current population size is uncertain.
West of the Continental Divide, the number of breeding colonies declined from 23-24 in the early 1900s 5-8 in 1984 (King and Anderson 2005). Several colonies of unknown but likely large size in California disappeared in the 1900s before breeding numbers had been documented (Shuford 2005). At the same time, new colonies became established (e.g., in Montana and British Columbia).
Population size declined through the 1960s and increased greatly through the early 2000s.
Degree of Threat: Medium
Comments: This species is highly sensitive to human intrusion into breeding colonies, which cause desertions and exposure of eggs and young to temperature extremes and gull predation (Knopf and Evans 2004). Loud and close passes by motor boats and low flying airplanes can cause bird to flee from nesting colonies or feeding or roosting areas (Knopf and Evans 2004).
Hydrological alterations by humans have resulted in a net loss of breeding and feeding areas (Murphy 2005), and these alterations remain an important potential limiting factor (Knopf and Evans 2004). Some hydrological changes have created or improved nesting habitat.
Diseases (particularly Type C botulism and West Nile virus) have caused significant die-offs and mortality in recent years and are a cause for concern (Rocke et al. 2005).
In some areas, pelicans fly long distances (hundreds of kilometers) from nesting areas to the closest suitable feeding areas, but may nevertheless breed successfully.
Ehrlich et al. (1992) noted that several nesting colonies were jeopardized by several consecutive years of drought, which may lower water levels and allow mammal predators (particularly coyote and raccoon) access to pelican breeding sites.
Shooting historically was a significant mortality factor and still is the greatest mortality factor resulting in band returns (Evans and Knopf 1993).
After the 1960s, hundreds of pelicans died yearly due to the ingestion of insecticides such as toxaphene, endrin, and dieldrin, and as recently as winter 1998-99, 800 American white pelicans died in Florida from poisoning by insecticides that were resuspended from flooded agricultural soils (Keith 2005). However, pesticides and mercury currently are not regarded as significant causes of reproductive failure or population decline (see Knopf and Evans 2004). However, there is concern that increased incidence and severity of disease in pelicans may be related to pesticide contamination (Murphy 2005).
Management Requirements: Maintain water levels where birds nest and forage. Limit or restrict access to breeding colonies especially during courtship and early incubation. Prevent shooting. Restrict pesticide usage.
Biological Research Needs: The relationship between pesticide contamination and vulnerability to disease needs to be investigated (Murphy 2005). Better information is needed on demographics and metapopulation dynamics.
Global Protection: Many to very many (13 to >40) occurrences appropriately protected and managed
Comments: Many nesting colonies are in protected areas. At least 13 colonies in the United States are in national parks or state or federal wildlife refuges; all colonies in Saskatchewan are designated wildlife refuges; Alberta prohibits approach within 0.5 miles or entry into 6 colonies from 15 Apr to 15 Sept (Sidle et al. 1985).
Needs: The larger colonies (500+ nests) should be protected. Some nesting areas need protection against incursion by coyotes and raccoons; predator exclusion fences have been used successfully (Madden and Restani 2005)..
Relevance to Humans and Ecosystems
There are no known adverse effects of American white pelicans on humans. They were previously persecuted because of the misperception that they compete with humans for fish prey, but American white pelicans eat mainly small fish with no commercial value.
American white pelicans are lovely, majestic birds that are appreciate by bird enthusiasts. Historically they were also hunted for sport.
American white pelican
The American white pelican (Pelecanus erythrorhynchos) is a large aquatic soaring bird from the order Pelecaniformes. It breeds in interior North America, moving south and to the coasts, as far as Central America and South America, in winter.
The German naturalist Johann Friedrich Gmelin described the American white pelican in 1789. The scientific name means "red-billed pelican", from the Latin term for a pelican, Pelecanus, and erythrorhynchos, derived from the Ancient Greek words erythros (ἐρυθρός, "red") + rhynchos (ῥύγχος, "bill").
The American white pelican rivals the trumpeter swan, with a similar overall length, as the longest bird native to North America. Both very large and plump, it has an overall length is about 50–70 in (130–180 cm), courtesy of the huge beak which measures 11.3–15.2 in (290–390 mm) in males and 10.3–14.2 in (260–360 mm) in females. It has a wingspan of about 95–120 in (240–300 cm). The species also has the second largest average wingspan of any North American bird, after the California condor. This large wingspan allows the bird to easily use soaring flight for migration. Body weight can range between 7.7 and 30 lb (3.5 and 13.6 kg), although typically these birds average between 11 and 20 lb (5.0 and 9.1 kg). One mean body mass of 15.4 lb (7.0 kg) was reported. Another study found mean weights to be somewhat lower than expected, with eleven males averaging 13.97 lb (6.34 kg) and six females averaging 10.95 lb (4.97 kg). Among standard measurements, the wing chord measures 20–26.7 in (51–68 cm) and the tarsus measures 3.9–5.4 in (9.9–13.7 cm) long. The plumage is almost entirely bright white, except the black primary and secondary remiges, which are hardly visible except in flight. From early spring until after breeding has finished in mid-late summer, the breast feathers have a yellowish hue. After moulting into the eclipse plumage, the upper head often has a grey hue, as blackish feathers grow between the small wispy white crest.
The bill is huge and flat on the top, with a large throat sac below, and, in the breeding season, is vivid orange in color as is the iris, the bare skin around the eye, and the feet. In the breeding season, there is a laterally flattened "horn" on the upper bill, located about one-third the bill's length behind the tip. This is the only one of the eight species of pelican to have a bill "horn". The horn is shed after the birds have mated and laid their eggs. Outside the breeding season the bare parts become duller in color, with the naked facial skin yellow and the bill, pouch, and feet an orangy-flesh color.
Apart from the difference in size, males and females look exactly alike. Immature birds have light grey plumage with darker brownish nape and remiges. Their bare parts are dull grey. Chicks are naked at first, then grow white down feathers all over, before moulting to the immature plumage.
Distribution and ecology
American white pelicans nest in colonies of several hundred pairs on islands in remote brackish and freshwater lakes of inland North America. The most northerly nesting colony can be found on islands in the rapids of the Slave River between Fort Fitzgerald, Alberta, and Fort Smith, Northwest Territories. About 10–20% of the population uses Gunnison Island in the Great Basin's Great Salt Lake as a nesting ground. The southernmost colonies are in southwestern Ontario and northeastern California. Nesting colonies exist as far south as Albany County in southern Wyoming.
They winter on the Pacific and Gulf of Mexico coasts from central California and Florida south to Panama, and along the Mississippi River at least as far north as St. Louis, Missouri. In winter quarters, they are rarely found on the open seashore, preferring estuaries and lakes. They cross deserts and mountains but avoid the open ocean on migration. But stray birds, often blown off course by hurricanes, have been seen in the Caribbean. In Colombian territory it has been recorded first on February 22, 1997, on the San Andrés Island, where they might have been swept by Hurricane Marco which passed nearby in November 1996. Since then, there have also been a few observations likely to pertain to this species on the South American mainland, e.g. at Calamar.
Wild American white pelicans may live for more than 16 years. In captivity, the record lifespan stands at over 34 years.
Food and feeding
Unlike the brown pelican (P. occidentalis), the American white pelican does not dive for its food. Instead it catches its prey while swimming. Each bird eats more than 4 pounds of food a day, mostly fish such as Cypriniformes like Common carp (Cyprinus carpio), Lahontan Tui chub (Gila bicolor obesa) and shiners, Perciformes like Sacramento perch (Archoplites interruptus) or Yellow perch (Perca flavescens), Salmoniformes like Rainbow trout (Oncorhynchus mykiss), Siluriformes (catfish), and jackfish[verification needed]. Other animals eaten by these birds are crayfish and amphibians, and sometimes larval salamanders. Birds nesting on saline lakes, where food is scarce, will travel great distances to better feeding grounds.
American white pelicans like to come together in groups of a dozen or more birds to feed, as they can thus cooperate and corral fish to one another. When this is not easily possible – for example in deep water, where fish can escape by diving out of reach –, they prefer to forage alone. But the birds also steal food on occasion from other birds, a practice known as kleptoparasitism. White pelicans are known to steal fish from other pelicans, gulls and cormorants from the surface of the water and, in one case, from a great blue heron while both large birds were in flight.
As noted above, they are colonial breeders, with up to 5,000 pairs per site. The birds arrive on the breeding grounds in March or April; nesting starts between early April and early June. During the breeding season, both males and females develop a pronounced bump on the top of their large beaks. This conspicuous growth is shed by the end of the breeding season.
The nest is a shallow depression scraped in the ground, in some twigs, sticks, reeds or similar debris have been gathered. After about one week of courtship and nest-building, the female lays a clutch of usually 2 or 3 eggs, sometimes just 1, sometimes up to 6.
Both parents incubate for about to one month. The young leave the nest 3–4 weeks after hatching; at this point, usually only one young per nest has survived. They spend the following month in a creche or "pod", moulting into immature plumage and eventually learning to fly. After fledging, the parents care for their offspring some three more weeks, until the close family bond separates in late summer or early fall, and the birds gather in larger groups on rich feeding grounds in preparation for the migration to the winter quarters. They migrate south by September or October.
Occasionally, these pelicans may nest in colonies on isolated islands, which is believed to significantly reduce the likelihood of mammalian predation. Red foxes and coyotes readily predate colonies that they can access, the later being the only known species to hunt adult pelicans (which are too large for most bird predators to subdue). Several gulls have been known to predate pelican eggs and nestlings (including herring, ring-billed and California gull), as well as common ravens. Young pelicans may be hunted by great horned owls, red-tailed hawks, bald eagles, and golden eagles. The pelicans react to mammalian threats differently from avian threats. Though fairly approachable while feeding, the pelicans may temporarily abandon their nests if a human or other large mammal closely approaches the colony. If the threat is another bird, however, the pelicans do not abandon the nest and may fight off the interloper by jabbing at them with their considerable bills.
Status and conservation
This species is protected by the Migratory Bird Treaty Act of 1918. It has the California Department of Fish and Game protective status California species of special concern (CSC). On a global scale however, the species is common enough to qualify as a Species of Least Concern according to the IUCN.
Habitat loss is the largest known cause of nesting failure, with flooding and drought being recurrent problems. Human-related losses include entanglement in fishing gear, boating disturbance and poaching as well as additional habitat degradation.
There was a pronounced decline in American white pelican numbers in the mid-20th century, attributable to the excessive spraying of DDT, endrin and other organochlorides in agriculture as well as widespread draining and pollution of wetlands. But populations have recovered well after stricter environmental protection laws came into effect, and are stable or slightly increasing today. By the 1980s, more than 100,000 adult American white pelicans were estimated to exist in the wild, with 33,000 nests altogether in the 50 colonies in Canada, and 18,500 nests in the 14–17 United States colonies. Shoreline erosion at breeding colonies remains a problem in some cases, as are the occasional mass poisonings when pesticides are used near breeding or wintering sites.
- BirdLife International (2012). "Pelecanus erythrorhynchos". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Elliott, Andrew (1992): 6. American White Pelican. In: del Hoyo, Josep; Elliott, Andrew & Sargatal, Jordi (eds.): Handbook of the Birds of the World (Vol. 1: Ostrich to Ducks): 310, plate 20. Lynx Edicions, Barcelona. ISBN 84-87334-10-5
- del Hoyo, J; Elliot, A; Sargatal, J (1996). Handbook of the Birds of the World 3. Barcelona: Lynx Edicions. ISBN 84-87334-20-2.
- CRC Handbook of Avian Body Masses by John B. Dunning Jr. (Editor). CRC Press (1992), ISBN 978-0-8493-4258-5.
- CRC Handbook of Avian Body Masses, 2nd Edition by John B. Dunning Jr. (Editor). CRC Press (2008), ISBN 978-1-4200-6444-5.
- Dorr, Brian S.; King, D. Tommy; Gerard, Patrick; and Spalding, Marilyn G. (2005) "The Use of Culmen Length to Determine Sex of the American White Pelican". USDA National Wildlife Research Center – Staff Publications. Paper 9.
- Estela, Felipe A.; Silva, John Douglas & Castillo, Luis Fernando (2005): El pelícano blanco americano (Pelecanus erythrorhynchus) en Colombia, con comentarios sobre los effectos de los huracanes en el Caribe [The American White Pelican (Pelecanus erythrorhynchus) in Colombia, with comments on the effects of Caribbean hurricanes]. Caldasia 27(2): 271- 275 [Spanish with English abstract]. PDF fulltext
- Dan A. Tallman, David L. Swanson, Jeffrey S. Palmer (2002). Birds of South Dakota (Hardcover ed.). Aberdeen, South Dakota: Midstates/Quality Quick Print. p. 10. ISBN 0-929918-06-1.
- Nesbitt, S.A.; Folk, M.J. (2003). "Kleptoparasitism of great blue herons by American white pelicans". Florida Field Naturalist 31 (2): 19–45.
- Dewey, Tanya. Pelecanus erythrorhynchos. Animal Diversity Web
- Blood, Donald A.; Hames, Michael; Graham, Arifin; Pawlas, Richard & Friis, Laura (1993) "American White Pelican" in Wildlife in British Columbia at Risk. Province of British Columbia Ministry of Environment, Lands and Parks. ISBN 0-7726-7466-3
Breeding on lakes throughout the northern Great Plains and mountain West, the American White Pelican is one of the largest birds in North America. It winters along the coasts, but breeds only inland.
The White Pelican does not dive for fish as the Brown Pelican does. Instead, it dips its head underwater to scoop up fish. Several pelicans may fish cooperatively, moving into a circle to concentrate fish, and then dipping their heads under simultaneously to catch fish.