Brown pelican

The brown pelican was described by Swedish zoologist Carl Linnaeus in the 1766 12th edition of his Systema Naturae, where it was given the binomial name of Pelecanus occidentalis. It belongs to the New World clade of the genus Pelecanus. The brown pelican is part of a clade that includes the Peruvian pelican (P. thagus) and American white pelican (P. erythrorhynchos); brown and Peruvian pelicans are sister taxa, with American white pelican a more distant relative. At least some of these subspecies are genetically distinct despite similar phenotypes. The subspecies differ from one another in size, coloration of the throat pouch (among other bare parts) in breeding condition, and/or certain breeding plumage details, as well as geographic range. == Description ==

The brown pelican is the smallest of the eight extant pelican species, but is often one of the larger seabirds in their range nonetheless. It measures in length and has a wingspan of . Like all pelicans, it has a very long bill, measuring in length. at the bottom for draining water when it scoops out prey. The breast and belly are dark, and the legs and feet black. The nonbreeding adult has a white head and neck, and the pre-breeding adult has a creamy yellow head. The pink skin around the eyes becomes dull and gray in the non-breeding season. It lacks any red hue, and the pouch is strongly olivaceous ochre tinged and the legs are olivaceous gray to blackish-gray. It has pale blue to yellowish white irides which become brown during the breeding season. During courtship, the bill becomes pinkish red to pale orange, redder at the tip, and the pouch is blackish. Later in the breeding season the bill becomes pale ash-gray over most of the upper jaw and the basal third of the mandible. It and the Peruvian pelican are the only true marine pelican species. The brown pelican produces a wide variety of harsh, grunting sounds, such as a low-pitched hrrraa-hrra, during displays. The adult also rarely emits a low croak, while young frequently squeal. ==Distribution and habitat==

The brown pelican lives on the Atlantic, Gulf, and Pacific Coasts in the Americas. On the Atlantic Coast, it is found from the New Jersey coast to the mouth of the Amazon River. After nesting, North American birds move in flocks further north along the coasts, returning to warmer waters for winter. In the non-breeding season, it is found as far north as Canada. Small numbers of brown pelicans have been recorded from Arica in far northern Chile. Along the Gulf Coast, it inhabits Alabama, Texas, Florida, Mississippi, Louisiana, and Mexico. It is also found in mangrove swamps, and prefers shallow waters, especially near salty bays and beaches. It avoids the open sea, seldom venturing more than 20 miles from the coast. Some immature birds may stray to inland freshwater lakes. Its range may also overlap with the Peruvian pelican in some areas along the Pacific coast of South America. It roosts on rocks, water, rocky cliffs, piers, jetties, sand beaches, and mudflats. Migration Most brown pelican populations are resident (nonmigratory) and dispersive (species moving from its birth site to its breeding site, or its breeding site to another breeding site). Some migration is observed, especially in the northern parts of the species's range, but these movements are often erratic, depending on local conditions. While usually restricted to coastal regions, brown pelicans occasionally wander inland, and there are records of vagrant individuals across much of the interior of North America. The species also occasionally wanders along the coasts of the Americas outside its normal range, with vagrants reported as far north as Southeast Alaska and Newfoundland, as far south as central Chile (well into the range of the closely related Peruvian pelican), and as far east in South America as Alagoas. Rare inland vagrants, generally caused by hurricanes or El Niño phenomena, have been reported from the Colombian Andes. They were first recorded in July 2009 in the Interandean Valley, where they remained for at least 161 days. There are four records far inland in Amazônia Legal, along the Amazon River and its tributaries. ==Behavior==

The brown pelican is a very gregarious bird; it lives in flocks of both sexes throughout the year. In level flight, brown pelicans fly in groups, with their heads held back on their shoulders and their bills resting on their folded necks. They may fly in a V formation, but usually in regular lines or single file, often low over the water's surface. To exclude water from the nasal passage, they have narrower internal regions of the nostrils. Feeding The brown pelican is a piscivore, primarily feeding on fish. Menhaden may account for 90% of its diet, and the anchovy supply is particularly important to the brown pelican's nesting success. Other fish preyed on with some regularity includes pigfish, pinfish, herring, sheepshead, silversides, mullets, sardines, minnows, and topminnows. Brown pelicans residing in Southern California rely especially heavily on pacific sardine as a major food source which can compose up to 26% of their diet, making them one of the top three predators of sardines in the area. Non-fish prey includes crustaceans, especially prawns, and it occasionally feeds on amphibians and the eggs and nestlings of birds (egrets, common murres and its own species). As the brown pelican flies at a maximum height of above the ocean, it can spot schools of fish while flying. often submerging completely below the surface momentarily as it snaps up prey. Besides its sister species, the Peruvian pelican, this is the only pelican to primarily forage via diving, all other extant pelican merely float on the waters' surface when foraging. Upon surfacing, it spills the water from its throat pouch before swallowing its catch. They are capable of drinking saline water due to the high capacity of their salt glands to excrete salt. Breeding The brown pelican is a monogamous breeder within a breeding season, but does not pair for life. Nesting season peaks during March and April. The male chooses a nesting site and performs a display of head movements to attract a female. although sometimes on cliffs, and less often in bushes or small trees. and consist of feather-lined impressions protected with a rim of soil and debris. The egg is chalky white, The young reach sexual maturity (and full adult plumage) at anywhere from three to five years of age. A brown pelican has been recorded to have lived for over 31 years in captivity. alligators, vultures, feral cats, feral dogs, raccoons, Predation is likely reduced if the colony is on an island. Although it is rare, bobcats have been documented eating both the offspring and injured adults. In California, adult brown pelicans have become a common prey item for North American river otters. The invasive red imported fire ant is known to prey on hatchlings. Like all pelicans, brown pelicans are highly sensitive to disturbances by humans (including tourists or fishermen) at their nests, and may even abandon their nests. Due to their size, non-nesting adults are rarely predated. ==Relationship with humans==

The brown pelican is now a staple of crowded coastal regions and is at some risk by fishermen (monofilament fishing line and hooks) and boaters. In the early twentieth century, hunting was a major cause of its death, and people still hunt adults for their feathers and collect eggs on the Caribbean coasts, in Latin America, and occasionally in the United States, even though it is protected under the Migratory Bird Treaty Act of 1918. In 1902, it was made a part of the official Louisiana seal and, in 1912, a pelican and her young became part of the Flag of Louisiana as well. One of Louisiana's state nicknames is "The Pelican State", and the brown pelican is the official state bird of Louisiana. It is one of the mascots of Tulane University, present on its seal, and is also present on the crest of the University of the West Indies. The National Basketball Association (NBA)'s New Orleans Pelicans are named in the honor of the brown pelican. In the 1993 film The Pelican Brief, based on the novel of the same name by John Grisham, a legal brief speculates that the assassins of two supreme court justices were motivated by a desire to drill for oil on a Louisiana marshland that was a habitat of the endangered brown pelican. In the same year, Jurassic Park showed a pod of brown pelicans at the end of the film. In the 2003 Disney/Pixar film Finding Nemo, a brown pelican (voiced by Geoffrey Rush in an Australian accent) was illustrated as a friendly, virtuous talking character named Nigel. Status and conservation Since 1988, the brown pelican has been rated as least concern on the IUCN Red List of Endangered species based on its large range—greater than 20,000 km2 (7700 mi2)—and an increasing population trend. In 1903, Theodore Roosevelt set aside Pelican Island, now known as Pelican Island National Wildlife Refuge, to solely protect the brown pelican from hunters. Starting in the 1940s with the invention and extensive use of pesticides such as DDT, the brown pelican population had drastically declined due to a lack of breeding success. By the 1960s, it had almost disappeared along the Gulf Coast and, in southern California, it had suffered almost total reproductive failure, due to DDT usage in the United States. A research group from the University of Tampa, headed by Ralph Schreiber, conducted research in Tampa Bay, and found that DDT caused the pelican eggshells to be too thin to support the embryo to maturity. In 1972, the United States Environmental Protection Agency (USEPA) banned DDT usage in the United States and limited the use of other pesticides. There has been a decline in chemical contaminant levels in brown pelican eggs since then, and a corresponding increase in its nesting success. In 2019 these declines were found to have reached levels which were a mere 10% of the highest reported abundances. The significant decrease in pacific sardine population can be linked to the levels of nitrogen within their habitat, a limiting factor in plankton production. These breeding failures have been characterized by decreased numbers of pelicans arriving at nesting colonies, large scale abandonment and early migration due to an inability to feed hatchlings, and sub-optimal breeding by those who do attempt to breed. Environmental changes tend to have fast acting impacts on marine bird populations due to the simplicity of their trophic cascade, allowing for complex, long term trends in ecosystem health and resources to be easily realized and tracked. Brown pelicans have proven to be a useful indicator in determining the effects of the well-established fishing industry in Southern California. Sardine fishery in the Gulf of California has been showing signs of overfishing since the early 1990s. Sardine population and abundance, however, is difficult to monitor and obtain indicators for. Since lacking food availability has negative implications for breeding success in seabirds, seabird diet, and breeding success have been used to indirectly measure the population status of the fish they feed on. This model has been shown to work using brown pelicans as an indicator species. As the proportion of sardines in the brown pelican's diet decreases, the success of fisheries declines to a lesser extent. When eventually the sardine abundance has declined enough for brown pelicans to move away and begin feeding on other forage fish, commercial fishing still would be fishing in significant numbers. This indicates that even when fisheries are not seeing signs of declining sardine abundance, brown pelicans may have already been affected to the point of locating other food sources. This availability of sardines may decline even further during El Niño anomalies, when thermoclines prevent brown pelicans from reaching their prey. Brown pelican diet will mostly indicate declines in sardine abundance for fisheries during the same season, as brown pelicans feed mostly on the same adult fish that are commercially fished. Although brown pelicans serve as an important indicator species for fisheries, declining sardine abundance due to both climate changes and overfishing have huge implications on overall ecosystem health, within or outside the individual trophic cascade. == Explanatory notes ==