The brown pelican is a large, plunge-diving seabird of the Americas and one of the most visible coastal birds along the warm shores of North, Central, and South America. Among the world's pelicans it is unusual: most species forage cooperatively while swimming, but the brown pelican hunts by diving headlong from the air to capture fish near the surface [Shields 2014]. Its history is also one of the best-documented conservation recoveries on record — populations crashed across the United States in the 1960s and early 1970s after the pesticide DDT and its metabolite DDE caused widespread eggshell thinning and reproductive failure [Blus et al. 1971; Blus et al. 1974], then rebounded after DDT was banned and protective measures took effect. This profile examines the species' biology, the contaminant-driven collapse and recovery, and the work that continues to safeguard it.
Biology and Identification
The brown pelican is a heavy-bodied waterbird with a body length of roughly 1.0–1.5 m and a wingspan of about 2.0–2.3 m; adult mass typically ranges from 2 to 5 kg, with males averaging larger than females [Shields 2014]. The defining feature shared by all pelicans is the large gular pouch suspended beneath the long, hooked bill, used as a dip-net to scoop fish and drain water before swallowing. Breeding adults develop a pale or yellowish crown and, in some populations, a chestnut-brown hindneck, while non-breeding birds are plainer with a white head and neck.
The species is almost exclusively piscivorous. Schooling fish dominate the diet, with menhaden and other small coastal fish forming the bulk of prey in much of its range [Shields 2014]. Its signature foraging method is the plunge-dive: the bird locates fish from the air, folds its wings, and drops bill-first into the water, a behavior shared among pelicans only with the closely related Peruvian pelican [Shields 2014].
Brown pelicans are colonial breeders, nesting on islands and other predator-poor sites in trees, shrubs, or on the ground depending on the locality. Clutches typically contain two to three eggs, incubated for roughly four weeks, with both parents sharing incubation and chick-rearing [Shields 2014]. Long-lived for a bird, individuals can survive well into their second and third decades. Eggs are incubated by the heat of the parents' webbed feet — a trait that made the species especially sensitive to anything that weakened the eggshell.
Habitat and Range
The brown pelican is a bird of shallow coastal and estuarine waters and is rarely found far out to sea or inland. Its breeding range spans both Atlantic and Pacific coasts of the Americas — from the Atlantic and Gulf coasts of the United States south through the Caribbean to northern South America, and along the Pacific from the western United States south to Chile, including the Galápagos Islands [Shields 2014; BirdLife International 2018]. It is a non-migratory or only partially dispersive species, with post-breeding movements that shift birds along the coast.
The species occupies a very large global range. The IUCN Red List assessment notes an extensive extent of occurrence, consistent with the bird's wide distribution across tropical and temperate American coastlines [BirdLife International 2018].
In accordance with NRWL sensitive-species policy, specific site locations, den or nest sites, and seasonal movement details are not disclosed in this article.
Conservation Status
The brown pelican is listed as Least Concern on the IUCN Red List, with an increasing global population trend [BirdLife International 2018]. The species has held this category in successive global assessments on the basis of its very large range and large, recovering population. It is not listed on any CITES appendix [CITES 2023].
This favorable global status follows a severe contaminant-driven decline in the United States during the mid-twentieth century. The brown pelican was first protected under U.S. federal endangered-species law in 1970, the year before the present Endangered Species Act was enacted [USFWS 2009]. After decades of recovery, the U.S. Fish and Wildlife Service removed the species from the federal list of endangered and threatened wildlife in a final rule effective December 17, 2009, citing increased population numbers and restored reproductive success following the U.S. ban on most uses of DDT [USFWS 2009]. The 2009 final rule documented that brown pelican numbers and breeding success had increased substantially across the former range, supporting the determination that the threats that had caused the decline were sufficiently reduced [USFWS 2009]. Even after delisting, the species remains protected in the United States under the Migratory Bird Treaty Act [USFWS 2009].
Threats
Organochlorine contamination (historical and instructive). The brown pelican's twentieth-century decline was driven chiefly by DDT and its persistent metabolite DDE, which accumulated through the marine food web and caused eggshell thinning so severe that eggs broke or failed during incubation. Eggs collected from colonies in the Carolinas, Florida, and California in 1969–1970 showed pervasive shell thinning and measurable DDE residues, and the contaminant was statistically linked to reduced reproductive success [Blus et al. 1971; Blus et al. 1974]. The eggshell-thinning effect of organochlorine pesticides on fish-eating and raptorial birds was a central scientific finding of the era [Hickey & Anderson 1968]. The U.S. ban on most uses of DDT in 1972 removed the principal driver of the collapse [USFWS 2009].
Oil spills. As a coastal, surface-foraging bird that nests on low islands, the brown pelican is highly exposed to marine oil pollution. The 2010 Deepwater Horizon spill in the Gulf of Mexico oiled large numbers of pelicans during the breeding season and damaged nesting habitat; oiled feathers lose their insulating and waterproofing function, and ingested oil can be toxic [NWF 2025].
Habitat loss and disturbance. Because the species nests colonially on a limited number of islands, loss or erosion of nesting islands, human disturbance at colonies, and degradation of coastal foraging habitat can have outsized effects on local populations [Shields 2014].
Fisheries interactions. Entanglement in fishing gear and ingestion of hooks and monofilament line are recurring local hazards where pelicans concentrate near piers, harbors, and fishing activity [Shields 2014].
What Is Being Done
Pesticide regulation. The regulatory action with the greatest demonstrated benefit to the brown pelican was the 1972 U.S. ban on most uses of DDT, which the Fish and Wildlife Service identified as central to the species' recovery and eventual delisting [USFWS 2009]. The pelican's collapse and rebound remain a textbook example of how reducing an environmental contaminant can reverse a population decline.
Legal protection and monitoring. Following the 2009 delisting, the Fish and Wildlife Service implemented post-delisting monitoring to confirm that the recovered population remained secure, and the species continues to be protected under the Migratory Bird Treaty Act [USFWS 2009]. Long-term colony surveys track breeding numbers and productivity across the U.S. range.
Habitat restoration. In the northern Gulf of Mexico, restoration projects funded through the Deepwater Horizon settlement have rebuilt eroded nesting islands used by brown pelicans and other colonial waterbirds. The restoration of Queen Bess Island off the Louisiana coast — long one of the state's most important pelican colonies — added tens of acres of nesting habitat that pelicans returned to use [NOAA 2021].
Refuges and protected colonies. Island colonies in the United States have a long history of formal protection; Pelican Island, established as the first U.S. national wildlife refuge in 1903, was created in part to protect breeding pelicans and remains emblematic of seabird-colony conservation [USFWS 2009].
How Readers Can Help
Citizen science. Log brown pelican sightings on platforms such as iNaturalist and eBird. Coastal observation records contribute to range mapping and to long-term tracking of breeding distribution and abundance.
Reduce fishing-gear hazards. Where pelicans gather near piers and harbors, retrieve cut line and discarded hooks, avoid feeding wild pelicans, and never cast near birds. Monofilament-recycling bins and responsible angling measurably reduce entanglement injuries to coastal seabirds.
Support coastal habitat and clean water. Back policies and projects that protect nesting islands, restore coastal wetlands, and prevent oil and contaminant pollution of estuaries — the same conditions that govern the brown pelican's food supply and breeding success.
Learn from the recovery. The brown pelican's rebound after the DDT ban is one of the clearest demonstrations that contaminant regulation works. Sharing that accurately — with attention to the science of eggshell thinning [Blus et al. 1971; Hickey & Anderson 1968] — strengthens public support for the environmental protections that made the recovery possible.
References
[BirdLife International 2018] BirdLife International. (2018). Pelecanus occidentalis. The IUCN Red List of Threatened Species 2018: e.T22733989A132663224. https://doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22733989A132663224.en
[Blus et al. 1971] Blus, L.J., Heath, R.G., Gish, C.D., Belisle, A.A. & Prouty, R.M. (1971). Eggshell thinning in the brown pelican: Implication of DDE. BioScience, 21(24), 1213–1215. https://doi.org/10.2307/1296019
[Blus et al. 1974] Blus, L.J., Neely, B.S., Belisle, A.A. & Prouty, R.M. (1974). Organochlorine residues in brown pelican eggs: Relation to reproductive success. Environmental Pollution, 7(2), 81–91. https://doi.org/10.1016/0013-9327(74)90075-5
[CITES 2023] CITES. (2023). Appendices I, II and III. Convention on International Trade in Endangered Species of Wild Fauna and Flora. https://cites.org/eng/app/appendices.php
[Hickey & Anderson 1968] Hickey, J.J. & Anderson, D.W. (1968). Chlorinated hydrocarbons and eggshell changes in raptorial and fish-eating birds. Science, 162(3850), 271–273. https://doi.org/10.1126/science.162.3850.271
[NOAA 2021] NOAA Gulf Spill Restoration. (2021). Restored Queen Bess Island welcomes home another pelican that persevered after Deepwater Horizon. https://www.gulfspillrestoration.noaa.gov/2021/06/restored-queen-bess-island-welcomes-home-another-pelican-persevered-after-deepwater-horizon
[NWF 2025] National Wildlife Federation. (2025). 15 years later: Reflecting on the Deepwater Horizon oil spill's legacy in the Gulf. https://blog.nwf.org/2025/04/15-years-later-reflecting-on-the-deepwater-horizon-oil-spills-legacy-in-the-gulf/
[Shields 2014] Shields, M. (2014). Brown Pelican (Pelecanus occidentalis), version 2.0. In The Birds of North America (A.F. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.609
[USFWS 2009] U.S. Fish & Wildlife Service. (2009). Endangered and Threatened Wildlife and Plants; Removal of the Brown Pelican (Pelecanus occidentalis) From the Federal List of Endangered and Threatened Wildlife. Final rule, effective December 17, 2009. Federal Register, 74(220), 59444–59472. https://www.federalregister.gov/documents/2009/11/17/E9-27402/endangered-and-threatened-wildlife-and-plants-removal-of-the-brown-pelican-pelecanus-occidentalis