A huge bird with a massive wingspan, the American white pelican (Pelecanus erythrorhynchos) has a sturdy bill and expandable pouch that are so large that this bird has an almost comical appearance. The brilliant white plumage contrasts strongly with conspicuous black primary feathers, pale orange legs and feet, a pinkish bill, and a yellow patch around the eye. During the breeding season, yellow feathers develop on the head, chest and neck and the feet become bright orange-red. The bill turns bright orange and a large, flattened, vertical horn develops on the upper mandible (2)(3)(4).
The male and female American white pelican are similar in appearance, but the juvenile is largely brownish with a dark crown and a pale grey bill (4).
Extremely graceful in flight, the American white pelican flies in ‘V’ shaped or diagonal formations, alternating between gliding and flapping, with the head tucked back into the shoulders. It often makes use of thermals to lift its bulky frame to great heights, but in the absence of thermals, it flies into the wind, staying close to the water surface and using the uplift caused by wind rising off the waves (2)(3). However, it is less elegant on land, with the short legs and webbed feet limiting movement to a clumsy waddle with the wings spread for balance (3).
Foraging in large flocks that cooperate to drive prey towards shallow water, the American white pelican catches its prey by dipping its large bill into the water while in flight, to scoop up fish into the pouch. The pouch is then drained of water and the prey is swallowed before transporting it back to the nest. The American white pelican is also known to occasionally pirate food from other bird species (2)(3)(4)(5).
Around three weeks before courtship begins, the American white pelican arrives at foraging grounds near to breeding colonies, which are on islands surrounded by freshwater that have no terrestrial predators. Breeding pairs search for a nesting site close to that of another pair at the same stage of breeding, so that the chicks will not be attacked by older chicks. The nest is a shallow depression in the ground, lined with a little vegetation. Higher-lying areas are preferred for nesting, to reduce the chance of flooding (2).
Two eggs are laid over a two-day period and then incubated by both adults for approximately 30 days (2)(3)(6). The chicks are fed on regurgitated food and, after approximately 17 days, gather with other chicks to form a crèche or pod. The chicks fledge after 10 to 11 weeks (2)(3).
The American white pelican breeds in parts of inland Canada and the northern United States, from British Columbia to Ontario, and from California east to Minnesota. Small breeding populations also occur on the central coast of Texas and occasionally in parts of Mexico (2).
In winter, the American white pelican moves south to the Pacific coast of the United States and Central America, from California south to Nicaragua. It also spends the winter around the Gulf Coast, from Florida to Mexico (2), and may reach as far south as Costa Rica (1).
The American white pelican is also an occasional visitor to some Caribbean islands (1).
The American white pelican underwent a dramatic decline in the first half of the 20th century, caused by overexploitation and habitat loss. Although it is now increasing in many parts of its range, this increase is restricted by human disturbance of breeding colonies, which can cause nesting birds to abandon their nests. This often causes the eggs to be exposed to temperature extremes, meaning the adults must incubate the eggs for a longer period, but it may also cause the eggs to be abandoned completely (2).
The American white pelican is also susceptible to contamination by toxic pollutants, which can accumulate in its body after eating contaminated prey. This can cause thinner eggshells to be produced and reduce reproductive success. Suitable breeding habitats are also being reduced, due to flooding of nesting islands or the drainage of lakes (2).
Historically, the American white pelican has also suffered from shooting for sport, or by the fishing industry in retaliation for predation on fish stocks. However, this threat is now much reduced (2).
After previous declines, protective legislation and increased public awareness have successfully contributed to the recovery of the American white pelican population. Where breeding sites are limited, artificial island habitats have been created far from the reaches of terrestrial predators, and fencing has been used successfully where nesting sites are accessible to terrestrial predators. Additional conservation priorities for the American white pelican include further protection of breeding colonies, including protection from human disturbance, as well as flood prevention and improved drainage (2).
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