Fowl ticks Carios maritimus and Ornithodoros denmarki are found in nests, but there are no documented cases of illness or death from these ectoparasites. Hippoboscid flies (Olfersia sordida) and epidermoptid mites (Myialges caulotoon) are two ectoparasites found on brown pelicans in the Galapagos Islands. In large numbers, mosquitoes can cause nest abandonment. Phagicola longus, Mesostephanus appendiculatoides, Galactostomum darbyi, and Stephanoprora denticulata are the four most prevalent of the 31 known helminths that inhabit the small intestine. One study found a mean of 7,134 helminths per bird, however, no known deaths have occurred as a result of these. Three species of diplostomes have been found in the small intestines of brown pelicans in Texas, which are Bolbophorus confusus, Bursacetabulus pelecanus, and Bursacetabulus macrobursus. Endoparasitic mites from the family Hypoderidae have been removed in subcutaneous tissues of the neck and trachea from brown pelicans in Florida and Louisiana. These include Phalacrodectes punctatissimus, Phalacrodectes pelecani, and Pelecanectes apunctatus. A study done on nestlings in Florida also found Coccidian sporozoa from Eimeria pelecani in fecal samples.
Commensal/Parasitic Species:
Humans, Homo sapiens are a serious predator of pelicans, hunting them for their meat, feathers, and eggs. Predatory birds, such as the fish crow (Corvus ossifragu) have been recorded destroying pelican eggs. Although it is rare, bobcats (Felis rufus) have been documented eating both the offspring and injured adults. Feral cats (Felis catus), feral dogs (Canus lupus familiaris), and raccoons (Procyon lotor) will eat the hatchlings when they are able. Two reptiles have been recorded preying on nestlings: Mexican spiny-tailed iguanas (Ctenosaura pectinata) and the American alligator (Alligator mississippiensis). Invasive species such as red imported fire ants (Solenopsis invicta) have infested nests and killed up to 60% of hatchlings in some calses. Although predation on adults is rare, they are occasionally attacked by sharks and sea lions (Otaria flavescens) while floating on the water. When approached by a predator, brown pelicans will usually flee individually without group cohesion. If it is during the incubation or brooding periods, parents will attempt to scare an approaching predator away before fleeing.
Known Predators:
Brown pelicans are easily distinguished by their large body, long bill, and very large gular pouch. They are the darkest plumed of the pelicans. They weigh 2 to 5 kg, and males are 15 to 20% heavier than females. They have a body length of 100 to 137 cm, a bill that ranges from 25 to 38 cm in length (10% longer in males than females), and an average wingspan of 200 cm (which is 3 to 6% longer in males). They have feet with webbing that stretches from the front to the hind toe. Their gular pouch is able to hold up to 3 gallons of water, which is 3 times more than what the stomach can hold. The distal portion of the gular pouch is a dark gray-green year round and during mating, the proximal area of the gular pouch turns a bright red. During incubation, the proximal area of the pouch turns back to the normal gray-green color.
During the first year, the underside is white and molt cycles are so rapid that definitive colors are not easily defined per molt. At around 10 weeks, molting starts and juvenile pelicans undergo 6 molts before reaching definitive basic plumage which then is slightly altered during breeding season. Around 3 to 5 years, plumage has developed, the upper areas turn gray to gray-brown, the abdomen turns a blackish-brown, and the remainder of the underside is striped with black and silver markings. During molting, adult pelicans can adopt up to 3 appearances. During post-breeding season the head becomes pale yellow and the neck becomes white. Immediately prior to breeding the head becomes yellow but the neck turns a dark brown color. During the nesting period, the head turns white with randomly-placed dark feathers and a brown neck. The plumage in males and females is similar except that females are likely to molt before males (females molt at 34 to 36 months; males at 36 to 40 months).
Juvenile brown pelicans display a brown iris which changes to a light tan or blue during courtship. After onset of incubation, the iris returns to a dark brown color. Additionally, juveniles display a black eye ring until 16 to 19 months, at which point it turns pale blue-black color. In adults, this eye ring is a gray-pink most of the year, changes to pink during mating, and then darkens to brown following onset of incubation.
Range mass: 2 to 5 kg.
Range length: 100 to 137 cm.
Average wingspan: 200 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Brown pelicans have a long lifespan. The oldest individual recorded in the wild was 43 years of age. About 30% of brown pelicans survive past the first year, and less than 2% survive longer than 10 years. Three banded individuals survived past the 20 year mark at 31, 37, and 43 years old. However these data may be incomplete because bands may corrode and fall off after 12 to 15 years. Hatched nestlings have been frequently recorded killing younger siblings either by directly pecking them on head or pushing them from nest, as well as indirectly by not allowing them to feed. The first hatched chick has a survival rate of 70% and one study found that up to 30% of nestlings in one breeding season were killed by the older sibling.
Range lifespan
Status: wild: 43 (high) years.
Average lifespan
Status: wild: 334 months.
Pelicans are strictly coastal, rarely living more than 20 miles or 32 km from the shoreline. They are found in warm coastal waters or marine estuaries during the non-breeding season. They require dry areas that are not subjected to frequent disturbance. They roost offshore at night and loaf during the day after or while foraging. Typical loaf and roost sites include sandbars, pilings, jetties, breakwaters, mangrove islets, and offshore rocks or islands. To breed, they move to small, predator-free islands. On the Atlantic and Gulf Coasts, brown pelicans are found breeding on barrier islands, natural estuarine islands, or dredge-spoil islands. Along the Pacific Coast and the northern Gulf of California they breed on dry, rocky islands. In mainland Mexico, they are found in mangroves. In the tropics, they inhabit coastal and inland mangroves and humid forests.
Habitat Regions: tropical ; terrestrial ; saltwater or marine
Aquatic Biomes: coastal
Wetlands: marsh ; swamp
Other Habitat Features: urban ; estuarine
Brown pelicans are found in warm, shallow waters throughout the nearctic and neotropical regions of both the Pacific and Atlantic oceans. Although considered strictly coastal, there are some records of brown pelicans living inland during the post-breeding season. Lake Okeechobee, FL and Salton Sea, CA are two locations where these birds have been documented off the coast. They breed in 10 coastal states in the U.S.: Maryland, Virginia, North Carolina, South Carolina, Georgia, Florida, Louisiana, Alabama, Texas, and California. In Mexico, brown pelicans are found on offshore islands, and coastal areas along the Caribbean and along the Gulf of Mexico. They have been found on the Pacific coasts in Honduras, Costa Rica, Belize, and Panama. South American sites include the Caribbean coast of Colombia, Venezuela, Aruba, and the Galapagos Island. The only colony on the Pacific coast in South America is in Ecuador. In the West Indies, sites have been documented in Cuba, Jamaica, Dominican Republic, Puerto Rico, U.S. Virgin Islands, British Virgin Islands, Barbuda, and Antigua.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Brown pelicans are carnivores, primarily feeding on fish but also small marine invertebrates. They are the only pelicans that dive for their food. Their astounding eyesight while in flight allows them to dive from up to 20 meters in the air. Although their eyesight is poor underwater, they can often be observed floating and feeding by surface-seizing with success. The lower jaw is split into two halves which turn out upon impact with the water's surface, forming a scoop with the gular pouch. Brown pelicans forage up to 20 km from their nesting sites and can travel up to 175 km from the mainland and 75 km from an island during non-breeding season from fall to early winter. Most are observed foraging close to shore but there are records of them diving up to 20 miles offshore and they are almost never seen feeding in freshwater lakes or streams. They are typically solitary while foraging, but if two or more forage together they will feed in sequence, driving fish towards the other(s). Foraging is most commonly observed in early morning and evening and occasionally at night during a full moon. Florida pelicans forage on small fish and some marine invertebrates in shallow waters, typically in water less than 150 meters deep.
Herring and fry fish in the Virgin Islands have been studied as being the fish of choice after being driven to the surface by other predatory fish such as sharks, salmon, and dolphins. From Cuba to Bermuda, stomach contents have shown herring, anchovies, sardines, and fry to all be consumed most frequently. Begging and scavenging on piers, docks, and boats can also make up a good portion of a their diet if they live within range of any of these. Laughing gulls (Laris atricilla) often steal food from their beaks, sometimes perching on their back and waiting for the opportunity. Although rare, brown pelicans have been observed stealing fish from the beaks of other birds as well.
The young are fed through regurgitation of pre-digested fish onto the nest floor and as much as 50 kg of fish is consumed from the hatchling to fledgling stage when raised in captivity. Although no comparable data has been collected on wild brown pelicans, captive adult pelicans have been recorded requiring 0.3 kg of fish per day during the summer months and 0.8 kg of fish per day during the winter months.
Not surprisingly, adult pelicans are more successful hunters than younger birds. A study in Southwest Mexico found that adult pelicans are successful 84% of time compared to only 75% of the time in juveniles. An even greater discrepancy was seen in a study done in Belize; adults were successful 83% of the time where juveniles only had a success rate of 43%. These differences in feeding success could be attributed to diving and prey-handling skills, patch choice, knowledge of appropriate dive heights, angles, and ability to determine likelihood of success. Adult birds were seen "wheeling" in the air but if chance of successful foraging was determined to be low they would continue flying. Juveniles would always dive after a "wheel" regardless of interpreted success, therefore wasting more energy when not successful. A study done in Florida showed a linear correlation between age of the brown pelican and success rate: pelicans less than one year old had 4% success rate, 12 to 22 month old pelicans had a 8% success rate, 22 to 40 month old pelicans had a 12% success rate, and adults older than 36 months had a success rate of 14%.
Brown pelicans are able to drink saltwater due to the salt gland that is unique to birds (although non-functional and smaller in birds that are not exposed to high salinity) which excretes excess salt. These glands are located on the anterior sides of the eyes and are 2.6 to 3cm in length and 0.6 to 0.8 cm in width. These glands are necessary because the kidney is only able to rid the body of half the salt ingested. These glands are able to excrete salt in such high concentrations that it makes the drinking of saltwater tolerable and aids in conservation of water.
Animal Foods: fish; aquatic crustaceans; other marine invertebrates
Primary Diet: carnivore (Piscivore )
Humans benefit from pelicans by hunting, egging, and trapping. Their meat and eggs are used for food and their feathers have commercial value. A charismatic species, they are also valuable for research and educational purposes.
Positive Impacts: food ; body parts are source of valuable material; research and education
Brown pelicans often specialize on schools of small fish. Although these fish are not directly beneficial to fisherman, they make up the diet of commercially important fish.
The IUCN Red List classifies brown pelicans as a species of least concern and the US Federal list gives them no special status. In the 1950's and 1960's, DDT was used as a pesticide and subsequently was passed through the food chain up to brown pelicans. This bioaccumulation altered the brown pelicans' physiology, decreasing the egg shell strength and causing eggs to break during incubation. In 1968 a restocking effort took plan in Louisiana, lasting for several years until 1976. During this time period 767 nestlings, 8 to 11 weeks in age, were transported to Louisiana from Florida and 221 nested in the area in which they were released. Despite a die-off in 1975 of about 40% of the population due to Endrin contamination, the brown pelican reached historical population sizes by 1990. Brown pelican were listed as endangered in 1970 but DDT was not outlawed until 1972. In 1985, brown pelicans was downgraded to threatened and in 2009 the species was removed from the list completely. Human disturbance, fish hooks and lines, oil spills, and human activities such as hunting, egging, and trapping threaten brown pelican populations. Annual surveys have found stable to increasing population size along with nesting success being recorded as having a high success rate. Pelicans are adjusted to boom-bust cycles and have adapted to hurricanes and El Nino effects which lower food availability. However, the long-term effects of the Gulf oil spill of 2010 are still unknown. During the oil spill, pelicans were the hardest hit, comprising 58% of bird mortality and injuries.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Brown pelicans communicate through visual cues, chemical signals, acoustically, and in a tactile manner. Adult brown pelicans will communicate, particularly during mate selection and nest site protection, with a low "hrraa-hrraa" sound and head swaying. Other interactions include bowing, which is usually more of a defensive behavior. Non-aggressive behaviors include swinging of head side to side, raising of bill horizontally and spreading wings outward, and cleaning the opposite side of the nearby pelican. Peeps from eggs can be heard up to 2 days prior to the start of hatching. Nestlings release a high pitched, scratchy call to their parents usually while the parents are searching for food.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Pelecanus occidentalis originates from the Greek word pelakan and the species name is Latin for "western".
Brown pelicans are seasonally monogamous and nest in irregular patterns. They migrate to 20 to 30 degrees north latitude to breed if they do not live in this range year-round. Nesting lasts throughout the year in certain tropical regions, but generally begins in late fall and lasts into early June. Those which nest between 20 and 30 degrees north latitude nest more regularly through winter into spring. However, those which nest 30 to 35 degrees north of the equator nest definitively in the spring and summer seasons. Nesting is controlled by a variety of factors including: time to nest successfully, molt length, day length fluctuations, food abundance, time when freezing temperatures occur, and timing of hurricane season. Local environmental conditions are the main factor in determining nesting seasons. Sites are used annually until changes in nesting habitat, food availability, or human disturbances induce colony relocation. Breeding locations are ideally within 30 to 50 km of a consistent food supply.
Male brown pelicans select a nest site prior to courtship and pair bond formation. Males protect a potential nest area and nearby perches for up to 3 weeks. Males initiate courtship rituals but both males and females participate. Rituals include head swaying, bowing, and turning. Both sexes also release a "low raaa" call. Courtship typically lasts 2 to 4 days before pair bonding occurs, but can last up to 21 days. As part of the pair bonding and nest building ritual, males present females with nesting materials. Building the nest can take up to 7 days. The first egg is laid 3 days after the completion of the nest.
Mating System: monogamous
The breeding season of brown pelicans varies with latitude, often coinciding with local food abundance. In Maryland, they begin to lay eggs in late May through early September with peaks of egg laying varying between years. In North Carolina, the laying season is mid-March through July. In Florida, egg laying periods vary from east to west coasts; egg laying is December to June on the Atlantic coast and January to June on the Gulf side. In Louisiana, the egg laying season was March to June up until the near extinction of the pelican population in this area. The new population now begins either in December or January and ends in June. Texas populations begin in March and last through June, with egg output peaking in April through May. In south California, egg laying starts in December, lasts until early August and peaks between February and May. In the Gulf of California, egg laying is November until May. In Panama, egg laying lasts from January until May. In west and southwest Puerto Rico, breeding peaks between September and November but in eastern Puerto Rico, brown pelicans breed year-round. In Venezuela, the breeding season is from November to June, peaking between January and February. In the U.S. Virgin Islands, as well as the Galapagos Islands, breeding is year-round.
Copulation occurs about 7 times before the first egg is laid and each act lasts 7 to 14 seconds. During copulation, the male grabs the female's upper neck with his bill, mounts her from behind, and holds her neck in this way until the act is over. The female is passive except for movements of her tail from side to side. Males perform a post mounting display by holding their bill open with their head set back upon the shoulders. Sometimes males will put on displays including bill throws and glottis exposure.
After courtship, pairs build nests in trees or on the ground, and stay in colonies. The optimal spot for ground nests is in medium-density vegetation 1 to 2 meters off the ground. This location allows their offspring to leave the nest earlier than those in trees, some as early as 3 weeks old. The most ideal location for a nest in a tree is a spot with nearby branches adequate for landing and taking off. Male brown pelicans bring the nest-building materials while females build the nests. Material is dependent on what is available at the nest site. Ground nests can be as simple as a shallow depression in the sands lined with grass or as complex as a full structure built out of sticks, grass stems, and seaweed. Nests in trees are typically made up of sticks, grass, or leaves. Males have been documented stealing from unattended nests as well as using man-made materials such as rope or window screening. Males will continue to bring the female building materials during incubation and until juveniles reach fledgling age.
Eggs have a textured surface and are chalky white in color. The number of eggs laid ranges from 1 to 4. Adult brown pelicans lay 3 eggs per season on average, while juvenile pelicans less than 3 years old lay no more than 2 eggs. Pelicans incubate eggs with their webbed feet. Both parents share responsibility for turning and incubating the eggs as well as protecting them from predation. The incubation period typically lasts 29 to 32 days and only about 70% of eggs laid in a season will hatch. Eggs are laid in 24 to 64 hour intervals but will still hatch within 1 day of one another. Brown pelicans in captivity have laid eggs to replace those lost during the nesting season. Brown pelican chicks have a have an egg-tooth on the tip of their beak which they use on the broadest part of the egg to break open the shell. After the initial peck, it usually takes 31 hours for the chicks to fully hatch. Initial weight of brown pelican chicks ranges from 54.9 to 87 grams with an average weight of 73.5 grams. Ten grams of this weight is egg yolk withheld in the abdomen. The egg tooth disappears within 10 days of hatching.
Newly hatched chicks have pinkish gray skin covered in fluff. On postnatal day 9, the chicks' skin has darkened. By day 10, they are lightly covered in a layer of white down which is fully developed by day 20. The legs and feet of brown pelicans less than 24 days old are a dull white color. This quickly changes to a dark grey or black when they are juveniles and into adulthood. Juvenile feathers appear at day 30 and these are kept until adult feathers develop by age 3. They fledge at 11 weeks and are considered independent at 3 months. At this time, they abandon the nest but stay within the vicinity of their birth site. A study found that after forced relocation, most returned to their birth site within 3 years. Those which did not return founded new colonies instead of joining existing ones. Variation in the choice to return or not seemed dependent on food availability and suitable locations for nesting. These nesting areas need to be dry due to the fact that pelicans cannot be directly exposed to water for over an hour without becoming waterlogged. Brown pelicans can mate as young as 2 but the average is 3 to 4 years old.
Breeding interval: Brown pelicans breed seasonally in colder climates and year-round in warmer climates.
Breeding season: The breeding season varies with latitude and often depends on local food availability.
Range eggs per season: 2 to 3.
Average eggs per season: 3.
Range time to hatching: 29 to 30 days.
Average time to hatching: 30 days.
Average fledging age: 11 weeks.
Average time to independence: 3 months.
Range age at sexual or reproductive maturity (female): 2 to 4 years.
Average age at sexual or reproductive maturity (female): 3-4 years.
Range age at sexual or reproductive maturity (male): 2 to 4 years.
Average age at sexual or reproductive maturity (male): 3-4 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average eggs per season: 2.
Both males and females work together to build the nest, incubate the eggs, protect the nest, feed and protect the young, and teach the offspring how to fly. Parents alternate guarding the nest until the offspring are 4 to 6 weeks old. Nestlings are ectothermic at birth and rely on their parents to maintain internal temperature. The development of endothermy begins with increased mass, changes in metabolic rates, and an increase in downy feathers. Initially young brown pelicans feed by pecking regurgitated fish off the nest floor, but as coordination increases, they begin to feed directly from their parents' mouths. After the first 4 to 6 weeks, parents spend less time in the nest and mostly return to feed their young. At 5 to 6 weeks, the parents no longer roost in the nest at night, but rather on nearby perches. Parents feed the young until 11 to 12 weeks of age, when the young reach the fledgling stage.
Parental Investment: male parental care ; female parental care ; pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
The brown pelican's image adorns postage stamps across the Americas, from Bermuda and Belize to Venezuela and St. Vincent and the Grenadines. It is Louisiana's state bird and the national bird for Turks and Caicos Islands.
With its dark plumage and distinct feeding methods, the brown pelican sets itself apart from seven other pelican species. Aside from being one of the smaller pelican species, the brown pelican is the only one that is known to dive and dine. Most pelican species feed by corralling fish into shallow waters through a group chase before scooping them up with their large beaks. Brown pelicans have their own distinct method: once they spot light reflecting off the scales of fish, they plunge into the water from heights of up to 70 feet where they scoop up fish, drain water through their beaks and tip their heads back to swallow (MarineBio.org: Brown Pelican, Pelecanus occidentalis, 2010 ). Air sacs beneath their skin protect them from injury when they hit the water (read more: General Description and Elkhorn Slough Birds: Brown Pelican.
The air sacs are also part of what helps these birds fly. Their body length measures 48 inches (1.2 m) on average, which is about the height of a nine-year old child. Yet their weight rarely exceeds 12 lbs (1.4 kg). The trick to keeping such a large bird aloft is not just a long wingspan, but a body made light through air sacs (AvianWeb.com, 2010).
The pelican's recent history is one of struggle against destructive human activities like unregulated hunting and pollution. Over the past century, their ill fortune has wrought positive change, inspiring the creation of one of the first bird refuges in the U.S. as well as a ban against toxic pesticides. Most recently, it became the inadvertent poster animal of the disastrous impact of the BP oil spill in the Gulf of Mexico. (read more: Conservation)
On a global scale, brown pelicans are doing just fine. The IUCN lists their status as being that of Least Concern, which means the world is in no danger of losing brown pelicans anytime soon. It is the particular populations that live in the Gulf of Mexico whose habitat has been affected as a result of the explosion of the Deepwater Horizon deep sea oil rig and the resulting oil spill (Allen-Mills, 2010).
This isn't the first time brown pelicans are getting worldwide sympathy. In the 19th century pelicans were hunted for their plumage, and few habitats were safe from hunters. In 1903 U.S. President Teddy Roosevelt formed the country's first wildlife refuge for birds. It was only a five-acre patch of land on Pelican Island in Florida, but it was the first step toward what is now the National Wildlife Refuge System, which today covers more than 95 million acres total (Benzel, 2010).
While protected areas can keep hunters out, they cannot block the entry of pesticides and other environmental contaminants. The widespread use of DDT was especially harmful the vulnerable shells of brown pelican eggs and highly detrimental to the brown pelican populations in North America. It was only after the U.S. banned the use of DDT in 1972 that their numbers began to pick up (Ehrlich, 1988).
It may only be a certain subspecies of the brown pelican that has been affected, but the situation still concerns scientists. Ornithologists say they are not sure whether Louisiana's brown pelicans will survive this latest environmental disaster (Drash, 2010).
The brown pelican (Pelecanus occidentalis) is a bird of the pelican family, Pelecanidae, one of three species found in the Americas and one of two that feed by diving into water. It is found on the Atlantic Coast from New Jersey to the mouth of the Amazon River, and along the Pacific Coast from British Columbia to northern Chile, including the Galapagos Islands. The nominate subspecies in its breeding plumage has a white head with a yellowish wash on the crown. The nape and neck are dark maroon–brown. The upper sides of the neck have white lines along the base of the gular pouch, and the lower fore neck has a pale yellowish patch. The male and female are similar, but the female is slightly smaller. The nonbreeding adult has a white head and neck. The pink skin around the eyes becomes dull and gray in the nonbreeding season. It lacks any red hue, and the pouch is strongly olivaceous ochre-tinged and the legs are olivaceous gray to blackish-gray.
The brown pelican mainly feeds on fish, but occasionally eats amphibians, crustaceans, and the eggs and nestlings of birds. It nests in colonies in secluded areas, often on islands, vegetated land among sand dunes, thickets of shrubs and trees, and mangroves. Females lay two or three oval, chalky white eggs. Incubation takes 28 to 30 days with both sexes sharing duties. The newly hatched chicks are pink, turning gray or black within 4 to 14 days. About 63 days are needed for chicks to fledge. Six to 9 weeks after hatching, the juveniles leave the nest, and gather into small groups known as pods.
The brown pelican is the national bird of Saint Martin, Barbados, Saint Kitts and Nevis, and the Turks and Caicos Islands, and the official state bird of Louisiana, appearing on the flag, seal, or coat of arms of each. It has been rated as a species of least concern by the International Union for Conservation of Nature. It was listed under the United States Endangered Species Act from 1970 to 2009, as pesticides such as dieldrin and DDT threatened its future in the Southeastern United States and California. In 1972, the use of DDT was banned in Florida, followed by the rest of the United States. Since then, the brown pelican's population has increased. In 1903, Theodore Roosevelt set aside the first National Wildlife Refuge, Florida's Pelican Island, to protect the species from hunters.
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.[2] It belongs to the New World clade of the genus Pelecanus.[3]
Five subspecies of the brown pelican are recognized.[4][5] 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.[6][7]
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.[5] The Peruvian pelican was previously treated as a subspecies of the brown pelican, but is now considered a separate species on the basis of its much greater size (around double the weight of the brown pelican), differences in bill color and plumage, and a lack of evidence of hybridization between the forms where their ranges approach and overlap.[3] (In captivity, the brown pelican is known to have hybridized with both the American white pelican and the more distantly-related great white pelican.[13])
In 1932, James L. Peters divided Pelecanus into three subgenera, placing brown pelican (including Peruvian pelican) in a monospecific Leptopelicanus, American white pelican in a monospecific Cyrtopelicanus, and all the rest in the subgenus Pelecanus, a treatment which was also followed by Jean Dorst and Raoul J. Mougin in 1979. Andrew Elliott in 1992, and Joseph B. Nelson in 2005, considered the deepest division among pelicans to lie between brown (plus Peruvian) pelican on the one hand, and the white-plumaged pelicans on the other (among which the large ground-nesting American white, Australian, great white, and Dalmatian pelicans were thought to form a clade, and the smaller tree-nesting pink-backed and spot-billed pelicans were likewise considered sister taxa). In 1993, Paul Johnsgard hypothesized that the Americas were colonized relatively late in pelican evolution, with the family originating in Africa or South Asia; however, he later supported the prevailing view that brown (with Peruvian) was the most divergent pelican (and considered American white and great white pelicans to be close relatives, implying two independent dispersals of pelicans into the Americas, with that of the ancestor of brown and Peruvian pelicans occurring early on). Sibley and Ahlquist's DNA-DNA hybridization studies and UPGMA tree published in 1990 supported brown pelican as sister to a clade comprising all the white-plumaged pelicans analyzed, including American white pelican (although the relationships among the latter group differed).[3]
With better genetic data and more modern methods, a new phylogenetic hypothesis of pelican relationships has arisen, which contrasts with the traditional view of brown and Peruvian being the most divergent pelicans based on their distinctive plumage and behavior (and early molecular data). Rather than the brown-plumaged pelicans and white-plumaged pelicans forming two reciprocally monophyletic groups, the American white pelican is sister to brown and Peruvian pelicans, the three together forming an exclusively New World pelican clade. (Among the other pelicans, pink-backed, Dalmatian, and spot-billed pelicans are close relatives, together sister to Australian pelican. Great white pelican has no particularly close relatives; while it may be sister to the previous four, this relationship had low statistical support.)[3]
The brown pelican is the smallest of the eight extant pelican species, but is often one of the larger seabirds in their range nonetheless.[14][15] It measures 1 to 1.52 m (3 ft 3 in to 5 ft 0 in) in length and has a wingspan of 2.03 to 2.28 m (6 ft 8 in to 7 ft 6 in).[5] The weight of adults can range from 2 to 5 kg (4.4 to 11.0 lb), about half the weight of the other pelicans found in the Americas, the Peruvian and American white pelicans. The average weight in Florida of 47 females was 3.17 kg (7.0 lb), while that of 56 males was 3.7 kg (8.2 lb).[16][17][18] Like all pelicans, it has a very long bill, measuring 280 to 348 mm (11.0 to 13.7 in) in length.[5]
The nominate subspecies in its breeding plumage has a white head with a yellowish wash on the crown. The nape and neck are dark maroon–brown. The upper sides of the neck have white lines along the base of the gular pouch, and the lower foreneck has a pale yellowish patch. The feathers at the center of the nape are elongated, forming short, deep chestnut crest feathers. It has a silvery gray mantle, scapulars, and upperwing coverts (feathers on the upper side of the wings), with a brownish tinge. The lesser coverts have dark bases, which gives the leading edge of the wing a streaky appearance. The uppertail coverts (feathers above the tail) are silvery white at the center, forming pale streaks. The median (between the greater and the lesser coverts), primary (connected to the distal forelimb), secondary (connected to the ulna), and greater coverts (feathers of the outermost, largest, row of upperwing coverts) are blackish, with the primaries having white shafts and the secondaries having variable silver-gray fringes. The tertials (feathers arising in the brachial region) are silver-gray with a brownish tinge.[5] The underwing has grayish-brown remiges with white shafts to the outer primary feathers. The axillaries and covert feathers are dark, with a broad, silver–gray central area. The tail is dark gray with a variable silvery cast. The lower mandible is blackish, with a greenish-black gular pouch[19] at the bottom for draining water when it scoops out prey.[20] The breast and belly are dark,[21] and the legs and feet black.[19] It has a grayish white bill tinged with brown and intermixed with pale carmine spots.[19] The crest is short and pale reddish-brown in color. The back, rump, and tail are streaked with gray and dark brown, sometimes with a rusty hue.[19] The male and female are similar, but the female is slightly smaller.[5] It is exceptionally buoyant due to the internal air sacks beneath its skin and in its bones. It is as graceful in the air as it is clumsy on land.[22]
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.[5]
The juvenile is similar, but is grayish-brown overall and has paler underparts.[23] The head, neck, and thighs are dusky-brown, and the abdomen is dull white.[5] The plumage of the male is similar to a fully adult female, although the male's head feathers are rather rigid.[19] The tail and flight feathers are browner than those of the adult. It has short, brown upperwing coverts, which are often darker on greater coverts, and dull brownish-gray underwing coverts with a whitish band at the center. The irides are dark brown and the facial skin is bluish. It has a gray bill which is horn-yellow to orange near the tip, with a dark gray to pinkish-gray pouch. It acquires adult plumage at over 3 years of age, when the feathers on the neck become paler, the upperparts become striped, the greater upperwing and median coverts become grayer, and the belly acquires dark spots.[5]
The brown pelican is readily distinguished from the American white pelican by its nonwhite plumage, smaller size, and habit of diving for fish from the air, as opposed to co-operative fishing from the surface.[24] It and the Peruvian pelican are the only true marine pelican species.[13]
The brown pelican produces a wide variety of harsh, grunting sounds, such as a low-pitched hrrraa-hrra, during displays.[5] The adult also rarely emits a low croak, while young frequently squeal.[13]
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The brown pelican lives on the Atlantic, Gulf, and Pacific Coasts in the Americas.[25] On the Atlantic Coast, it is found from the New Jersey coast to the mouth of the Amazon River.[26] Along the Pacific Coast, it is found from British Columbia to south-central Chile, including the Galapagos Islands.[26][27] After nesting, North American birds move in flocks further north along the coasts, returning to warmer waters for winter.[28] In the non-breeding season, it is found as far north as Canada.[1] It is a rare and irregular visitor south of Piura in Peru, where generally it is replaced by the Peruvian pelican, and can occur as a non-breeding visitor south at least to Ica during El Niño years.[29] Small numbers of brown pelicans have been recorded from Arica in far northern Chile.[27] It is fairly common along the coast of California, South Carolina, North Carolina, Georgia, the West Indies, and many Caribbean islands as far south as Guyana.[30] Along the Gulf Coast, it inhabits Alabama, Texas, Florida, Mississippi, Louisiana, and Mexico.[26]
The brown pelican is a strictly marine species, primarily inhabiting marine subtidal, warm estuarine, and marine pelagic waters.[31] It is also found in mangrove swamps, and prefers shallow waters, especially near salty bays and beaches.[31] It avoids the open sea,[1] seldom venturing more than 20 miles from the coast.[26] 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.[31]
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.[5]
The brown pelican is a very gregarious bird; it lives in flocks of both sexes throughout the year.[32] In level flight, brown pelicans fly in groups, with their heads held back on their shoulders and their bills resting on their folded necks.[33] They may fly in a V formation, but usually in regular lines or single file, often low over the water's surface.[34] To exclude water from the nasal passage, they have narrower internal regions of the nostrils.[35]
The brown pelican is a piscivore, primarily feeding on fish.[36] Menhaden may account for 90% of its diet,[37] and the anchovy supply is particularly important to the brown pelican's nesting success.[38] Other fish preyed on with some regularity includes pigfish, pinfish, herring, sheepshead, silversides, mullets, sardines, minnows, and topminnows.[39] 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.[40] 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).[41][42][43][44]
As the brown pelican flies at a maximum height of 18 to 21 m (60 to 70 ft) above the ocean, it can spot schools of fish while flying.[41] When foraging, it dives bill-first like a kingfisher,[45] often submerging completely below the surface momentarily as it snaps up prey.[46] 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.[47][48] Upon surfacing, it spills the water from its throat pouch before swallowing its catch.[46] Only the Peruvian pelican shares this active foraging style (although that species never dives from such a great height[27]), while other pelicans forage more inactively by scooping up corralled fish while swimming on the water surface. It is an occasional target of kleptoparasitism by other fish-eating birds such as gulls, skuas, and frigatebirds.[49] They are capable of drinking saline water due to the high capacity of its salt glands to excrete salt.[50]
The brown pelican is a monogamous breeder within a breeding season, but does not pair for life.[51] Nesting season peaks during March and April.[52] The male chooses a nesting site and performs a display of head movements to attract a female.[25] At the proposed nest site, major courtship displays such as head swaying, bowing, turning, and upright (standing on its legs without any support) are performed by both the sexes. They may also be accompanied by low raaa calls.[51]
Once a pair forms a bond, overt communication between them is minimal. It is a colonial species, with some colonies maintained for many years. Probably owing to disturbance, tick infestation, or alteration in food supply, colonies frequently shift.[5] It nests in secluded area, often on islands, vegetated spots among sand dunes, thickets of shrubs and trees, and in mangroves,[23] although sometimes on cliffs, and less often in bushes or small trees.[1] Nesting territories are clumped, as individual territories may be at a distance of just 1 m (3.3 ft) from each other.[51] They are usually built by the female from reeds, leaves, pebbles, and sticks,[53] and consist of feather-lined impressions protected with a 10 to 25 cm (3.9 to 9.8 in) rim of soil and debris.[13] They are usually found 0.9 to 3 m (3 to 10 ft) above the ground.[23] Renesting may occur if eggs are lost from the nest early in the breeding season.[51]
There are usually two to three, or sometimes even four, oval eggs in a clutch, and only one brood is raised per year.[23][54] The egg is chalky white,[52] and can measure about 76 mm (3.0 in) in length and 51 mm (2.0 in) in width.[23] Incubation takes 28 to 30 days with both sexes sharing duties, keeping the eggs warm by holding them on or under their webbed feet. It takes 28 to 30 days for the eggs to hatch,[23] and about 63 days to fledge.[5] After that, the juvenile leave the nest and gather into small groups known as pods.[23] The newly hatched chicks are pink and weigh about 60 g (0.13 lb).[51][53] Within 4 to 14 days, they turn gray or black.[53] After that, they develop a coat of white, black or grayish down.[53] Fledging success may be as high as 100% for the first hatched chick, 60% for the second chick, and just 6% for the third chick.[51]
The parents regurgitate predigested food for the young to feed upon until they reach their fledging stage.[55] After about 35 days, the young venture out of the nest by walking.[13] The young start flying about 71 to 88 days after hatching.[54] The adults remain with them until some time afterwards and continue to feed them.[23] In the 8- to 10-month period during which they are cared for, the nestling pelicans are fed by regurgitated, partially digested food of around 70 kg (150 lb) of fish.[56] The young reach sexual maturity (and full adult plumage) at anywhere from three to five years of age.[57] A brown pelican has been recorded to have lived for over 31 years in captivity.[5]
An adult brown pelican with a chick on a nest on Smith Island, Chesapeake Bay, Maryland, USA
Juvenile brown pelican in flight, Bodega Head, California
Predation is occasional at colonies, and predators of eggs and young (usually small nestlings are threatened but also occasionally up to fledgling size depending on the size of the predator) can include gulls, raptors (especially bald eagles), spiny-tailed iguanas,[58] alligators, vultures, feral cats, feral dogs, raccoons,[58] fish crows, and corvids.[59][60][61][62][63] 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.[58] Predation on adult brown pelicans is rarely reported, but cases where they have fallen prey to bald eagles have been reported. Also, South American sea lions and unidentified large sharks have been observed to prey on adult brown pelicans by seizing them from beneath while the birds are sitting on ocean waters.[64][65] The invasive red imported fire ant[66] is known to prey on hatchlings.[67] 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.[68] Due to their size, non-nesting adults are rarely predated.[13] Brown pelicans have several parasitic worms such as Petagiger, Echinochasmus, Phagicola longus, Mesostephanus appendiculatoides, Contracaecum multipapillatum, and Contracaecum bioccai, from its prey diet of black mullets, white mullets, and other fish species.[59]
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.[5][26]
The brown pelican is the national bird of Saint Martin, Barbados, Saint Kitts and Nevis, and the Turks and Caicos Islands.[69] 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.[70] One of Louisiana's state nicknames is "The Pelican State",[71] and the brown pelican is the official state bird of Louisiana.[72] It is one of the mascots of Tulane University, present on its seal,[55] and is also present on the crest of the University of the West Indies.[73] The National Basketball Association (NBA)'s New Orleans Pelicans are named in the honor of the brown pelican.[74]
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 1998, American conductor David Woodard performed a requiem for a California brown pelican on the seaward limit of the berm of a beach where the animal had fallen.[75][76]: 152–153 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.[77][a]
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.[1] The population size is also well beyond the threshold for vulnerable species.[1] The nominate race population is thought to number at least 290,000 in the West Indies,[5] and 650,000 globally.[80] In 1903, Theodore Roosevelt set aside Pelican Island, now known as Pelican Island National Wildlife Refuge, to solely protect the brown pelican from hunters.[81]
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.[26] The brown pelican was listed under the United States Endangered Species Act from 1970 to 2009.[82] 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.[61] 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.[26] It became extinct in 1963 in Louisiana.[5] Between 1968 and 1980, the Louisiana Department of Wildlife and Fisheries' reintroduction program re-established the brown pelican, and its population numbers in California and Texas were restored due to improved reproduction and natural recolonization of the species. By 1985, its population in the eastern United States, including Florida, Georgia, South Carolina, Alabama, and northward along the Atlantic Coast, had recovered and the species was removed from the Endangered Species List.[26] Its population has grown by about 68% per decade over a period of 40 years in North America, and this trend appears to be continuing.[5] It is still listed as endangered in the Pacific Coast region of its range and in the southern and central United States. Although the United States Gulf Coast populations in Louisiana and Texas are still listed as endangered, they were recently estimated in 2009 about 12,000 breeding pairs. Since that time the Deepwater Horizon oil spill has adversely affected populations, and current population figures are not available.[26]
The brown pelican abundance has steadily recovered from the drastic population decreases in the 1940s, however bottom up control threatens the Southern California populations as food sources become diminished. It is common for forage fish populations to experience regular fluctuations, however there has been a consistent decrease in the Pacific sardine population beginning as early as 2014.[83] In 2019 these declines were found to have reached levels which were a mere 10% of the highest reported abundances.[40] Fluctuations in sardine populations have largely been attributed to bottom-up control, primarily including climate variability and ocean temperature.[84] The significant decrease in pacific sardine population can be linked to the levels of nitrogen within their habitat, a limiting factor in plankton production.[84] Pacific sardines in the California current system rely on wind driven upwelling to push cooler, nitrogen rich waters towards the surface, maintaining a sustainable, nutrient abundant environment.[84] Continued environmental disruptions, such as El Niño, rising ocean temperatures, and increased commercial fishing, have drastic effects on nutrient cycling within the California current system, leading to lasting impacts on Pacific sardine productivity and reproductive success.[85][84]
The brown pelican has been predicted to have high vulnerability to declining sardine populations .[40] At the lowest levels of sardine abundance, the brown pelican population has been predicted to decline up to 50%.[40] Even with a more moderate decline in sardine abundance (50% relative abundance), brown pelicans have been predicted to decrease by up to 27%.[40] A recent decline in brown pelican breeding success coincides with the population decline of the Pacific sardine.[40] Between 2014 and 2016, brown pelicans experienced a continuous breeding failure.[86] 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.[86] Breeding success is greatly reduced by oceanic anomalies, specifically warm-phase anomalies that increase the intensity of upwellings.[85] Increased upwellings disrupt marine productivity and forage fish availability.[85] These trends have important implications for the health and conservation of brown pelicans, as well as other seabirds.[86]
Seabirds have become increasingly important as an indicator species. They are often used in order to indirectly track changes in fish stocks, ecosystem health, and climate change.[87] 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.[88] 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.[89] Sardine population and abundance, however, is difficult to monitor and obtain indicators for.[89] 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.[89] 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.[85] 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.[85] 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.[85] This availability of sardines may decline even further during El Niño anomalies, when thermoclines prevent brown pelicans from reaching their prey.[85] 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.[85] 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.
{{cite web}}: CS1 maint: url-status (link) {{cite book}}: CS1 maint: multiple names: authors list (link) The brown pelican (Pelecanus occidentalis) is a bird of the pelican family, Pelecanidae, one of three species found in the Americas and one of two that feed by diving into water. It is found on the Atlantic Coast from New Jersey to the mouth of the Amazon River, and along the Pacific Coast from British Columbia to northern Chile, including the Galapagos Islands. The nominate subspecies in its breeding plumage has a white head with a yellowish wash on the crown. The nape and neck are dark maroon–brown. The upper sides of the neck have white lines along the base of the gular pouch, and the lower fore neck has a pale yellowish patch. The male and female are similar, but the female is slightly smaller. The nonbreeding adult has a white head and neck. The pink skin around the eyes becomes dull and gray in the nonbreeding season. It lacks any red hue, and the pouch is strongly olivaceous ochre-tinged and the legs are olivaceous gray to blackish-gray.
The brown pelican mainly feeds on fish, but occasionally eats amphibians, crustaceans, and the eggs and nestlings of birds. It nests in colonies in secluded areas, often on islands, vegetated land among sand dunes, thickets of shrubs and trees, and mangroves. Females lay two or three oval, chalky white eggs. Incubation takes 28 to 30 days with both sexes sharing duties. The newly hatched chicks are pink, turning gray or black within 4 to 14 days. About 63 days are needed for chicks to fledge. Six to 9 weeks after hatching, the juveniles leave the nest, and gather into small groups known as pods.
The brown pelican is the national bird of Saint Martin, Barbados, Saint Kitts and Nevis, and the Turks and Caicos Islands, and the official state bird of Louisiana, appearing on the flag, seal, or coat of arms of each. It has been rated as a species of least concern by the International Union for Conservation of Nature. It was listed under the United States Endangered Species Act from 1970 to 2009, as pesticides such as dieldrin and DDT threatened its future in the Southeastern United States and California. In 1972, the use of DDT was banned in Florida, followed by the rest of the United States. Since then, the brown pelican's population has increased. In 1903, Theodore Roosevelt set aside the first National Wildlife Refuge, Florida's Pelican Island, to protect the species from hunters.
