Pelicans develop slowly compared to most birds, spending months dependent on their parents and then years maturing before they breed for the first time. A brown pelican chick hatches nearly naked and helpless, does not fledge until roughly 11 to 12 weeks of age, and won’t attempt to breed until it is three to five years old. The oldest brown pelican on record lived to 43, so the species invests in a long life rather than rapid reproduction. That drawn-out timeline, combined with modern threats from fishing gear to climate change, means every stage of a pelican’s life carries distinct risks worth understanding.
Before the Egg Even Cracks
Pelican life begins with communication. American white pelican embryos start vocalizing before they have fully hatched. From the moment the chick begins to pip through the shell, it utters short, harsh squawks, especially when the nest contents are exposed to changes in temperature. Those calls are not random noise. They trigger brooding behavior in the attending parent, which shuffles its feet over the nest and nudges eggs or chicks back toward the center. After hatching, the chick adds a distinct begging call to its repertoire, and long sequences of begging prompt the parent to adopt a feeding posture and deliver food.1Elsevier / ScienceDirect (Animal Behaviour). Embryonic and neonatal vocal elicitation of parental brooding and feeding responses in american white pelicans
Pelicans typically lay two or three eggs, and they hatch asynchronously, meaning the first egg hatches a day or more before the last. This staggered start creates a size hierarchy among chicks from the very beginning. In brown pelican nests, siblicide is common. The oldest, largest chick often attacks or outcompetes the younger ones, and not all hatchlings survive. Research on brown pelican broods found that when a brood was reduced from three chicks to two, the first-hatched chick’s food supply stayed the same while the second-hatched chick actually received less food, since parents reduced their total deliveries after brood reduction rather than redistributing evenly.2PubMed. Does brood reduction provide nestling survivors with a food bonus? The surviving senior chick does not get a windfall of extra meals. Brood reduction in pelicans seems to be more about matching brood size to available resources than about concentrating food on a single favored offspring.
Growing Up in the Nest
Pelican chicks grow fast once they get going. By three to four weeks of age, brown pelican young are large enough to swallow whole fish. They get those fish in a dramatic fashion, thrusting their bills deep into their parent’s throat pouch and forcing the adult to regurgitate. It looks violent to human observers, but it is the standard feeding method for the family. The parent carries partially digested fish in its expandable gular pouch, and the chick essentially reaches inside to retrieve the meal. As the chicks grow, they become increasingly mobile around the nest site, gathering in groups called crèches where they huddle together while the adults are off foraging.
By around 11 to 12 weeks, brown pelican chicks are able to fly and begin to fend for themselves.3Birds of the World (Cornell Lab of Ornithology). Brown Pelican (Pelecanus occidentalis) That fledging moment is not a clean break. Newly independent juveniles are clumsy fliers and poor fishers, and the transition from parental feeding to self-sufficiency is the most dangerous period of a young pelican’s life. Many juveniles starve during their first months alone.
Learning to Fish
Fishing is not instinctive in the way most people assume. Pelicans plunge-dive from the air to catch fish near the surface, and the technique requires practice. Juvenile pelicans are measurably worse at it than adults. A study of Galápagos pelicans found that when juveniles dove on their own, they caught fish on roughly a third of their attempts. But when juveniles copied the behavior of adults, diving at the same times and in the same areas, their success rate jumped to about 57 percent. Even that improved rate was still below adult performance.4PLoS One. Juvenile Galápagos Pelicans Increase Their Foraging Success by Copying Adult Behaviour
Social learning plays a real role in pelican development. Juveniles that foraged near adults were nearly twice as successful as those hunting alone. This has practical implications for conservation: juvenile pelicans that end up isolated from experienced adults, whether because of habitat fragmentation or colony disruption, may face steeper odds of surviving their first year. The pattern also helps explain why juveniles congregate around fishing piers and harbors, where the fish are concentrated and the hunting is easier, even though those locations bring their own dangers.
The Years Before Breeding
Brown pelicans do not reach sexual maturity until they are three to five years old.5Birds of the World (Cornell Lab of Ornithology). Brown Pelican (Pelecanus occidentalis) That is a long adolescence by bird standards. During those pre-breeding years, juvenile and immature pelicans look noticeably different from breeding adults. Young brown pelicans have brownish plumage on the head and neck rather than the white and chestnut tones of breeding adults, and they lack the vivid gular pouch coloring that adults display during courtship.
That pouch color turns out to be biologically meaningful. In California brown pelicans, the redness of the gular pouch before breeding season has been linked to long-term survival prospects. Research on pelicans rehabilitated after the 2010 Deepwater Horizon oil spill found that post-spill birds lagged behind the general population in growing their ornamental yellow crown feathers, though their transition to white hind-neck plumage was not significantly different. Interestingly, gular pouch redness in the rehabilitated birds was more strongly influenced by whether the bird was wearing a GPS tracking tag than by its history of oil contamination. But among the post-spill birds, those with redder gular pouches in the first 18 months after release survived longer.6PubMed Central. Use of plumage and gular pouch color to evaluate condition of oil spill rehabilitated California brown pelicans (Pelecanus occidentalis californicus) post-release Pouch color, in other words, appears to be an honest signal of a pelican’s overall health and condition.
Colony Breeding and Synchronized Nesting
When pelicans finally reach breeding age, they nest in colonies that can number in the hundreds or thousands. American white pelicans form dense, synchronized nesting clusters within a larger colony. Groups of newly paired birds that are at the same stage of the reproductive cycle bunch together into subcolonies. As more birds arrive, additional subcolonies form nearby, each commonly at a different stage, so a single colony island might have one cluster incubating eggs while another is still in courtship.7Birds of the World (Cornell Lab of Ornithology). American White Pelican (Pelecanus erythrorhynchos)
This staggered arrangement means that colony sites remain active for months. It also means that disturbance at a colony does not necessarily affect every nest equally. A storm or predator intrusion might wipe out one subcolony’s eggs while another subcolony, a few weeks behind in development, has not yet laid. The social structure of pelican colonies provides a kind of built-in insurance, though it depends on the colony site being large enough and undisturbed enough to support multiple subcolonies.
Both parents share incubation and chick-rearing duties. In brown pelicans, incubation lasts about 28 to 30 days, with parents taking turns on the nest. Because pelicans lack a brood patch (the bare skin patch most birds use to warm eggs), they incubate by covering their eggs with their large webbed feet, which have an increased blood supply during the breeding season. This unusual incubation method made the species especially vulnerable to eggshell-thinning chemicals, a point that became catastrophically clear in the mid-twentieth century.
How Long Pelicans Live
Pelicans are long-lived for birds of their size. The oldest brown pelican on record reached 43 years of age.5Birds of the World (Cornell Lab of Ornithology). Brown Pelican (Pelecanus occidentalis) That is exceptional, and most individuals do not come close. First-year mortality is high, driven by the difficulty of learning to fish, exposure to predators, and vulnerability to human-caused hazards. Once a pelican survives past its first year or two, its annual survival rate improves considerably, and adults that make it to breeding age can potentially reproduce for decades.
This life-history strategy, in which a species invests in a long reproductive lifespan rather than producing many offspring quickly, makes populations sensitive to threats that reduce adult survival. A sudden spike in adult mortality from an oil spill, disease outbreak, or mass starvation event can take years to recover from, because the species simply does not produce young fast enough to bounce back quickly. It also means that threats concentrated on juveniles, such as fishing-gear entanglement near piers, can suppress recruitment into the breeding population even when adult birds look healthy.
Fishing Gear and the Hazards of Piers
Pelicans and recreational fishing overlap heavily, and the results are often grim for the birds. A study of brown pelicans near Tampa Bay’s Sunshine Skyway fishing pier found that fishing hooks and lines were the single most common cause of injury. Out of over 2,600 pelicans rescued from the Skyway pier and surrounding areas, fishing-related injuries accounted for the majority of diagnoses. The survival rate for pelicans with fishing-related injuries was just 59 percent, far lower than for birds admitted with other conditions like emaciation (86 percent survival) or toxin exposure (97 percent). A fishing-related injury cut a pelican’s odds of survival roughly in half compared to other diagnoses.8Avian Conservation and Ecology. Brown Pelicans and fishing piers: a comparative analysis of rehabilitation admissions from the “longest fishing pier in the world” to surrounding areas
Juveniles bear a disproportionate share of the damage. A separate survey at Tampa Bay fishing piers recorded 150 injured pelicans over the study period, and 81 percent of those were juveniles.9PubMed Central. Angler perceptions of pelican entanglement reveal opportunities for seabird conservation on fishing piers in Tampa Bay This skew makes sense given that young birds are both more likely to hang around piers (where fish scraps are easy pickings) and less experienced at avoiding lines and hooks. Among the pelicans that died in the Skyway study, immatures vastly outnumbered adults. Because these young birds have not yet entered the breeding population, the losses are invisible in nest counts but can quietly erode the species’ future.
Anglers are generally aware of the problem. The same Tampa Bay survey found that most fishers could identify entangled pelicans and supported conservation measures, but interventions like gear restrictions during peak pelican season had mixed results. Injuries were actually more frequently observed during the gear restriction season than during the unrestricted season, possibly because more pelicans congregate at piers during those months regardless of regulation.
The DDT Legacy and Eggshell Thinning
No account of pelican threats is complete without DDT. Beginning in the late 1940s, the pesticide DDT accumulated in aquatic food chains, and its metabolite DDE concentrated in the tissues of fish-eating birds at the top of those chains. Brown pelicans were among the hardest hit. Eggs from wild brown pelicans collected in the post-1945 era exhibited significant eggshell thinning, a pattern confirmed by laboratory studies in which kestrels fed DDT-contaminated diets showed the same effect.10Environmental Pollution. Clarification of effects of DDE on shell thickness, size, mass, and shape of avian eggs
Thinner shells cracked under the weight of incubating parents, and entire colonies went years without fledging a single chick. Brown pelican populations along the Gulf and Pacific coasts collapsed. The species was listed as endangered in the United States in 1970 and became one of the emblematic successes of the Endangered Species Act after DDT was banned in 1972. Populations gradually recovered as DDE residues declined in the food chain, and the brown pelican was delisted in 2009. The recovery took nearly four decades, a timeline that reflects both the slow clearance of persistent chemicals and the pelican’s unhurried reproductive pace.
Climate Change, Disease, and Shrinking Habitat
Contemporary threats are different in character from DDT but potentially just as serious. Sea level rise threatens the low-lying islands and coastal habitat where pelicans nest. A modeling study of future coastal erosion vulnerability found that about 23 percent of high-density brown pelican nesting habitat faces increased vulnerability to sea level rise, a proportion that is lower than for some other coastal-nesting seabirds but still substantial.11The Journal of Wildlife Management. Effects of future sea level rise on coastal habitat Storm surges during incubation can inundate entire subcolonies of nests, and those events are projected to become more frequent as sea levels climb.
Disease is an emerging concern as well. Highly pathogenic avian influenza reached South American pelican populations in late 2022. In Peru, the Peruvian pelican suffered dramatic losses. Between November 2022 and March 2024, during overlapping avian influenza and El Niño events, pelican abundance within marine protected areas dropped by roughly 32 to 38 percent. Population counts swung widely, ranging from fewer than 2,000 to over 52,000 depending on the season and survey timing.12Marine Ornithology. Updating the status of the Peruvian Pelican Pelecanus thagus following avian influenza and El Niño events in Peru El Niño suppresses the upwelling of cold, nutrient-rich water that supports anchovy populations, so the pelicans faced simultaneous pressure from disease and food scarcity. The combination illustrates how multiple stressors can compound in ways that neither would produce alone.
Migration and Seasonal Movement
Not all pelicans migrate, but many do, and the patterns vary by species and population. American white pelicans breed on inland lakes and marshes across the northern Great Plains and intermountain West of North America, then migrate south and to coastal areas for the winter. Brown pelicans are more sedentary along their subtropical and tropical range, though northern populations shift southward after breeding season. Advances in tracking technology have allowed researchers to map individual-level movements across seasons and years, capturing fine-scale flight characteristics, migratory pathways, and seasonal habitat use that earlier band-recovery studies could only approximate.13Birds of the World (Cornell Lab of Ornithology). American White Pelican (Pelecanus erythrorhynchos)
For juveniles, the first migration is another critical survival filter. Young American white pelicans must navigate hundreds or thousands of miles to wintering grounds they have never seen, relying on a combination of innate orientation and social cues from older birds in the flock. Pelicans are soaring birds that use thermals to gain altitude and then glide long distances, which makes their migration routes sensitive to weather patterns and topography. Wind farms, power lines, and other aerial obstacles along migration corridors pose collision risks, and these hazards have drawn increasing attention as tracking data reveals exactly which routes pelicans use.
Brown pelicans, being coastal and largely non-migratory in the southern parts of their range, face a different set of movement challenges. Post-breeding dispersal can take young birds far from their natal colony, and juveniles banded in the Gulf of Mexico have turned up along the Atlantic seaboard. This wandering phase is normal and probably serves to reduce competition with adults at breeding colonies, but it also exposes young pelicans to unfamiliar environments and hazards they have not encountered before, from different fishing-pier configurations to new predator communities.