SPECIES CODE: B02L
Listed Endangered (35 FR 16047-16048, 1970 October 13) in entire range except Atlantic coast of the United States, Florida and Alabama, where it was delisted (50 FR 4938-4945, 1995 February 04) due to recovery.
The adult brown pelican is a large dark gray-brown water bird with white about the head and neck. Immatures are gray-brown above and on the neck, with white underparts. This species can reach up to 8 pounds and larger individuals have a wing spread of over 7 feet.
The brown pelican eats mainly fishes, especially menhaden, mullet, sardines, pinfish, and anchovies in U.S. waters; sometimes euphausiids. Brown pelicans dive into the water from the air (USFWS 1980). They forage in shallow estuarine and inshore waters, mostly within 10 km of the Coast (Johnsgard 1993). Pelicans are rarely reported scavenging or preying on eggs or young of water birds.
REPRODUCTION AND DEVELOPMENT:
Brown pelicans nest in colonies mostly on small coastal islands, protected from mammal predators, especially raccoons. All courtship behavior is confined to the nest site. The male carries nesting materials to the female and she builds the nest. The nests are usually built in mangrove trees of similar size vegetation, but ground nesting may also occur. Ground nests may consist of sticks, reeds, straws, palmetto leaves, and grasses. Tree nests are made of similar material only they are more firmly constructed. Normal clutch size for this species is three eggs. Both males and females share in incubation and rearing duties. Birds seldom venture more than 20 miles out to sea and most foraging occurs in shallow estuarine waters. They use sand spits and offshore sand bars for loafing and nocturnal roost areas. The species is considered to be long-lived; one pelican captured in Florida, in 1964, had been banded in September 1933, over 31 years previously.
RANGE AND POPULATION LEVEL:
The brown pelican has a large range extending from North America to South America. The Caribbean brown pelican (Pelecanus occidentalis occidentalis) occurs only in Puerto Rico and the U.S. Virgin Islands. Estimates from informal observations completed in 1991 indicate that the current Caribbean population is 1,500 to 1,800 birds. The eastern brown pelican (Pelecanus occidentalis carolinensis) occurs in North Carolina, South Carolina, Florida, Louisiana, Mississippi, Texas, and in the Barrier Islands. Estimates completed in 1990 indicate that the population in North Carolina was 2,912 breeding pairs; 6,345 nesting pairs in South Carolina; and 32,750 pre-nesting birds and a total population of 57,250 birds after the nesting season in Florida.
Habitat of the brown pelican is mainly coastal; these birds are rarely seen inland or far out at sea. They feed mostly in shallow estuarine waters, less often up to 40 miles from shore. Pelicans make extensive use of sand spits, offshore sand bars, and islets for nocturnal roosting and daily loafing, especially by nonbreeders and during the non-nesting season. Dry roosting sites are essential. Some roosting sites eventually may become nesting areas.
Pelican nests are usually located on coastal islands, on the ground or in small bushes and trees (Palmer 1962). Brown pelicans nest on the middle or upper parts of steep rocky slopes of small islands in California and Baja California; they usually nest on low-lying islands landward of barrier islands or reefs on Atlantic and Gulf coasts, where they often nest in mangroves, sometimes in Australian "pines," red-cedars, live oaks, redbays, or sea grapes. In the subtropics and tropics, mangrove vegetation constitutes an important roosting and nesting substrate (Collazo and Klaas 1985, Schreiber 1979, Schreiber and Schreiber 1982). Pelicans may shift between different breeding sites, apparently in response to changing food supply distributions (Anderson and Gress 1983) and/or to erosion/flooding of nesting sites.
Populations (especially in California, Texas, and Louisiana) were decimated in the U.S. by pesticides (DDT and related compounds) in the 1950s and 60s. In the U.S. Caribbean, 7% of the pelican population in 1982 died as a result of fish die-offs in connection to chemical runoffs (e.g., organophosphates).
Populations are extremely vulnerable to chemical/pesticide pollution, which can result in eggshell thinning (reproductive failure) (Anderson and Hickey 1970, Blus et al. 1974), and presumably lethal poisoning. Other threats include disturbance of nesting birds by humans (reduces reproductive success), declining fish (food) populations, increased turbidity (e.g., from dredging, resulting in reduced visibility of prey); oil and other chemical spills, entanglement in fishing gear, shooting, extreme weather conditions (freezing of soft parts, destruction of nest sites by hurricanes, storms), disease, and parasitism. Human disturbance (e.g., recreational boating, poaching) not only disrupts reproductive success (Anderson and Keith 1980; Schreiber 1979), but may affect distribution patterns and age structure of pelicans using roosting sites during the nonbreeding season (Jaques and Anderson 1987). Habitat degradation affects both roosting and nesting patterns. On the Gulf Coast, nesting efforts have failed because nesting sites are susceptible to flooding as a result of continued site erosion (McNease et al. 1992).
Anderson, D.W., and F. Gress. 1983. Status of a northern population of California
brown pelicans. Condor 85:79-88.
Johnsgard, P.A. 1993. Cormorants, darters, and pelicans of the world. Smithsonian Inst.
Press, Washington, D.C. xiv + 445 pp.
NatureServe. 2003. NatureServe Explorer: An online encyclopedia of life [web application]. Version 1.8. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Accessed on February 11, 2004).
Palmer, R.S. (Ed.). 1962. Handbook of North American birds. Vol. 1. Loons through
flamingos. Yale University Press, New Haven. 567 pp.
U.S. Fish and Wildlife Service. 1980. Selected vertebrate endangered species of the
seacoast of the United States-brown pelican eastern and California subspecies. FWS/OBS-80/01.40.