American White Pelican Life History

Habitat

Habitat Lakes and PondsAmerican White Pelicans breed mainly on isolated islands in freshwater lakes or, in the northern Great Plains, on ephemeral islands in shallow wetlands. They forage in shallow water on inland marshes, along lake or river edges, and in wetlands, commonly 30 miles or more from their nesting islands. Where late summer temperatures bring sunning fish near the surface, these pelicans can forage on deeper lakes. During migrations, they stop in similar habitats to forage and rest. Catfish aquaculture farms in the Mississippi Delta have become increasingly popular spring migration stops for more easterly migrating flocks. In the winter, they favor coastal bays, inlets, estuaries, and sloughs where they can forage in shallow water and rest on exposed spots like sandbars. They rarely winter inland, though the Salton Sea in Southern California is a regular exception. Other inland sites may include large rivers where moving water prevents surface ice, including stretches below dams. Back to top

Food

Food FishAmerican White Pelicans eat mostly small fish that occur in shallow wetlands, such as minnows, carp, and suckers. Schooling fish smaller than one half their bill length predominate, though they will take sluggish bottom feeders, salamanders, tadpoles, and crayfish. They may also take deeper water fish like tui chub that spawn in the shallows. Because they are opportunistic, their diet changes with water levels and prey species abundance. In some areas of the Great Plains, salamanders and crayfish can predominate in the pelicans' diet. These birds can take game fish like cutthroat trout during spawning runs when locally available. Their prey is usually of little commercial value, although catfish aquaculture ponds in the Mississippi Delta have become an increasingly favored food source in recent years, especially during spring migrations. Back to top

Nesting

Nest Placement

Nest GroundThe pair chooses a relatively flat nest site on gravel, sand, or soil near other pelicans at the same stage of the breeding cycle. In southern, drier regions, they nest amongst sparse vegetation. In forested regions, sites may be under shrubs or trees.

Nest Description

Both sexes use their bills to rake up surrounding gravel, sand, or soil to create a shallow depression roughly 2 feet across with a rim usually no more than 8 inches high. Occasionally they dig into the bottom of the site as well and may include nearby vegetation, though neither of the pair leaves the site to gather material. Because of trampling, by the end of the nesting season, the broad cup is usually 2 inches deep at most.

Nesting Facts
Egg Length:3.3-3.7 in (8.3-9.5 cm)
Egg Width:2.0-2.2 in (5.2-5.5 cm)
Nestling Period:63-70 days
Egg Description:Uniform chalky white, rough to the touch, becoming smooth and discolored over time.
Condition at Hatching:Naked and helpless, with an orange body and grayish white pouch and bill, unable to walk.
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Behavior

Behavior DabblerThese large, gregarious birds often travel and forage in large flocks, sometimes traveling long distances in V-formations. They soar gracefully on very broad, stable wings, high into the sky in and between thermals. On the ground they are ungainly, with an awkward, rolling, but surprisingly quick walk. Their webbed feet make for water-ski landings and strong swimming. They forage by swimming on the surface, dipping their bills to scoop up fish, then raising their bills to drain water and swallow their prey. They also forage cooperatively: groups of birds dip their bills and flap their wings to drive fish toward shore, corraling prey for highly efficient, synchronized, bill-dipping feasts. Pairs court in circling flights and in strutting, bowing, and jabbing displays at a chosen nest sites. Though females lay two eggs, only one chick per nest usually survives—one harasses or kills the other (a behavior known as siblicide). At 2 to 3 weeks old, chicks leave their nests and form into groups called crèches. Parents continue to forage for them, returning to the creche and searching out their young to feed them. Pelicans respond to threats by flying aggressively into a near-stall or, on land, adopting an upright posture and grunting. More severe threats from aerial predators provoke open-billed displays where the pelican lunges forward, jabbing with its enormous bill. Predators include foxes, coyotes, gulls, ravens, Great Horned Owls, and Bald Eagles.Back to top

Conservation

Conservation Low ConcernPopulations of American White Pelicans have rebounded from lows in the mid-twentieth century and have grown at roughly 5 percent per year between 1966 and 2014, resulting in a tenfold increase, according to the North American Breeding Bird Survey. Waterbird Conservation for the Americas estimates a global breeding population in excess of 120,000. The species rates an 11 out of 20 on the Continental Concern Score and is assigned a status of Moderate Concern. They are not on the 2014 State of the Birds Watch List. These shy pelicans are highly sensitive to human disturbances at their breeding colonies and readily abandon nests. They used to be shot either for sport or from the idea that they competed with humans for fish—though they are now understood to take fish of little commercial value. However, as their numbers have grown, their spring migration stopovers at catfish aquaculture ponds in the Mississippi Delta have increased, and shootings there have increased. Historically, human disturbance and destruction of foraging and breeding habitat have been major threats. Water management on the breeding grounds has effects on pelicans, too, since they depend on shallow wetlands. Either permanent flooding or permanent draining of wetlands renders those habitats inhospitable.Back to top

Credits

Knopf, Fritz L. and Roger M. Evans. 2004. American White Pelican (Pelecanus erythrorhynchos), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Kushlan, J. A., M. J. Steinkamp, K. C. Parsons, J. Capp, M. A. Cruz, M. Coulter, I. Davidson, L. Dickson, N. Edelson, R. Elliott, R. M. Erwin, S. Hatch, S. Kress, R. Milko, S. Miller, K. Mills, R. Paul, R. Phillips, J. E. Saliva, W. Sydeman, J. Trapp, J. Wheeler and K. Wohl (2002). Waterbird conservation for the Americas: The North American waterbird conservation plan, version 1. Washington, DC, USA. 

Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.

North American Bird Conservation Initiative. 2014. The State of the Birds 2014 Report. US Department of Interior, Washington, DC, USA.

Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, Jr. Ziolkowski, D. J. and W. A. Link. The North American Breeding Bird Survey, results and analysis 1966-2013 (Version 1.30.15). USGS Patuxtent Wildlife Research Center 2014b. Available from http://www.mbr-pwrc.usgs.gov/bbs/.

Sibley, D. A. (2014). The Sibley guide to birds, second edition. Alfred A. Knopf, New York, USA.

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