The Brown Pelican is a permanent resident of the coastal marine environment from central North America southward to northern South America. Whether perched atop a piling, panhandling at a fishing pier, or gliding above the surf, this conspicuous and popular seabird is instantly recognizable by its large body, long bill, and enormous gular pouch. Webbing between all 4 toes on each foot makes the Brown Pelican a strong swimmer but an awkward walker. In flight, however, the species comes into its own. Long wings gracefully carry individuals to and from their fishing grounds, and flocks often fly in lines just above the water's surface, slowly rising and falling in a wavelike pattern. Superb fishers, Brown Pelicans are noted for their spectacular head-first dives to trap unsuspecting fish in their expandable pouches. Of the world's 8 pelican species, only the Brown Pelican and the closely related Peruvian Pelican (P. thagus) feed by this plunge-diving method. They also are the only truly marine and predominantly dark-plumaged pelican species.
Brown Pelicans are highly social year-round and breed in colonies of up to several thousand pairs. They typically nest on small estuarine or offshore islands, where they are free from disturbance and predation by terrestrial mammals, including humans.
Pairs build nests on the ground or in trees, depending on the substrate available; incubate eggs under their foot webs; and feed small young predigested fish that they regurgitate onto the nest floor. By 3-4 weeks of age, the young are large enough to swallow whole fish, which they obtain by thrusting their bills into their parents' throats, forcing them to disgorge. The young are able to fly and begin to fend for themselves by 11-12 weeks of age, but do not reach sexual maturity until 3-5 years of age. This is a long-lived species: The oldest individual on record died at 43 years of age.
Despite its longevity and popularity, the Brown Pelican nearly disappeared from North America between the late 1950s and early 1970s. Extensive scientific investigations revealed the culprit to be human-made organochlorine pesticides entering the marine food web. The pesticide endrin killed pelicans directly, whereas DDT impaired reproduction by causing individuals to lay thin-shelled eggs that broke under the weight of incubating parents. Both effects led to serious population declines. Breeding colonies along the Pacific and Gulf coasts of the United States were particularly hard hit. So vast was the devastation that, ironically, the species disappeared altogether from Louisiana, the "Pelican State," by 1963. In 1970, the Brown Pelican was placed on the Federal Endangered Species List. The plight of this and other species led to a ban on the use of DDT in the United States in 1972 and a reduction in the use of endrin during the 1970s. Reproduction soon improved, and pelican numbers began to rise. Recovery was so successful that the Brown Pelican was removed from the Endangered Species List in the southeastern United States in 1985 and in the remainder of its range in 2009. Once a symbol of the detrimental effects of pollution in marine ecosystems, the Brown Pelican now symbolizes the success of wildlife-conservation efforts.
This account draws heavily on the vast amount of Brown Pelican research conducted during the pesticide era, as well as more recent investigations. It necessarily emphasizes the well-studied North American populations, but data on Middle and South American populations are included when available.