Pelecanus occidentalisbrown pelican

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Geographic Range

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. (Sheilds, 2002)

Habitat

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. (Sheilds, 2002; Tangley, 2009)

Physical Description

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. (Bartholomew and Dawsom, 1954; Schreiber, 1980; Sheilds, 2002; Tangley, 2009)

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). (Bartholomew and Dawsom, 1954; Schreiber, 1980; Sheilds, 2002; Tangley, 2009)

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. (Bartholomew and Dawsom, 1954; Schreiber, 1980; Sheilds, 2002; Tangley, 2009)

  • Sexual Dimorphism
  • male larger
  • Range mass
    2 to 5 kg
    4.41 to 11.01 lb
  • Range length
    100 to 137 cm
    39.37 to 53.94 in
  • Average wingspan
    200 cm
    78.74 in

Reproduction

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. (Miller, 1983; Nellis, 2001; Schreiber, 1980; Sheilds, 2002)

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. (Miller, 1983; Nellis, 2001; Schreiber, 1980; Sheilds, 2002)

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. (Bartholomew and Dawsom, 1954; Miller, 1983; Nellis, 2001; Robinson and Dindo, 2011; Sheilds, 2002)

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. (Bartholomew and Dawsom, 1954; Miller, 1983; Nellis, 2001; Robinson and Dindo, 2011; Sheilds, 2002)

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. (Bartholomew and Dawsom, 1954; Miller, 1983; Nellis, 2001; Robinson and Dindo, 2011; Sheilds, 2002)

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. (Bartholomew and Dawsom, 1954; Miller, 1983; Nellis, 2001; Robinson and Dindo, 2011; Sheilds, 2002)

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. (Bartholomew and Dawsom, 1954; Miller, 1983; Nellis, 2001; Robinson and Dindo, 2011; Sheilds, 2002)

  • 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
  • Average eggs per season
    2
    AnAge
  • 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

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. (Bartholomew and Dawsom, 1954; Nellis, 2001; Schreiber, 1980; Sheilds, 2002)

  • 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

Lifespan/Longevity

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. (Nellis, 2001)

Behavior

Brown pelicans are diurnal, although they have been observed foraging at night during full moons. A 1986 study monitored a pelican via a transmitter for 68.8 daylight hours. The bird spent 32% of this time active and 68% inactive. It was never active at night, minimally active during twilight hours, and most active during daylight hours. Brown pelicans sleep on land either standing on both feet, or resting on their breast and belly, with their head on their shoulder and their bill tilted towards the side. When sunbathing, they usually spread one wing to the side, and rarely both. When bathing, they plunge their head below the surface, spreading their wings and beating their wings against the water's surface. After bathing, brown pelicans use their bills to spread oil secreted by the uropygial gland onto their feathers. (Nellis, 2001; Pennycuick, 1982; Schreiber and Schreiber, 1982; Schreiber, 1977)

Brown pelicans are the only species in the pelican family that dives from the air as their primary means of obtaining food. They have air sacs which allow them to be very buoyant in the water. They never swim below the surface but will plunge their head below it in an attempt to catch prey. They paddle their webbed feet to move around on the water's surface. On land they tend to be clumsy and can use their wings for better balance by extending them outwards. In the air they alternate between gliding and flapping, with an average flap rate of 2.4 beats between gliding intervals. They glide just above the water's surface to decrease drag at an average speed of 11.7 meters per second. During takeoff they extend their necks, and then pull their head back onto the shoulders once in flight. (Nellis, 2001; Pennycuick, 1982; Schreiber and Schreiber, 1982; Schreiber, 1977)

Brown pelicans are territorial of their nesting area. Threat displays include head swaying, which indicates readiness to interact. Defensive displays, often done when another pelican comes too close to the nest, include bowing followed by a "hrraa-hrraa" sound. Brown pelicans will avoid physical confrontation by displays of head swaying or raising their bill horizontally while spreading their wings. Play behaviors have been observed in nestlings, such as dismantling the nest or throwing sticks or shells into the air then retrieving them. Brown pelicans will defend their nest if intruders enter, often killing young pelicans who come too close. (Nellis, 2001; Pennycuick, 1982; Schreiber and Schreiber, 1982; Schreiber, 1977)

Brown pelicans in northern ranges migrate south in autumn, returning during the months of March and April. The cold weather and decreased availability of surface prey induce migration. Small populations of brown pelicans do remain in the northern ranges during the the winter months. Thousands have been documented in North and South Carolina. Those flocks in warmer climates typically will not migrate. (Nellis, 2001; Pennycuick, 1982; Schreiber and Schreiber, 1982; Schreiber, 1977)

Home Range

Brown pelicans forage within 20 km of their nesting site during the breeding season. During the non-breeding season they forage up to 175 km from the mainland and 75 km from an island. (Sheilds, 2002)

Communication and Perception

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. (Schreiber, 1980)

Food Habits

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. ("The California Brown Pelican recovery plan", 1983; Brandt, 1984; Carl, 1987; Nellis, 2001; Schnell, et al., 1983; Sheilds, 2002)

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 California Brown Pelican recovery plan", 1983; Brandt, 1984; Carl, 1987; Nellis, 2001; Schnell, et al., 1983; Sheilds, 2002)

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. ("The California Brown Pelican recovery plan", 1983; Brandt, 1984; Carl, 1987; Nellis, 2001; Schnell, et al., 1983; Sheilds, 2002)

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%. ("The California Brown Pelican recovery plan", 1983; Brandt, 1984; Carl, 1987; Nellis, 2001; Schnell, et al., 1983; Sheilds, 2002)

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. ("The California Brown Pelican recovery plan", 1983; Brandt, 1984; Carl, 1987; Nellis, 2001; Schnell, et al., 1983; Sheilds, 2002)

  • Animal Foods
  • fish
  • aquatic crustaceans
  • other marine invertebrates

Predation

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. (Nellis, 2001)

Ecosystem Roles

Fowl ticks Carios capensis 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. (Sheilds, 2002)

Commensal/Parasitic Species
  • fowl ticks Carios capensis
  • fowl ticks Ornithodoros denmarki
  • hippoboscid flies Olfersia sordida
  • epidermoptid mites Myialges caulotoon
  • helminth worms Phagicola longus
  • helminth worms Mesostephanus appendiculatoides
  • helminth worms Mesostephanus appendiculatoides
  • helminth worms Galactostomum darbyi
  • helminth worms Stephanoprora denticulata
  • diplostomes Bolbophorus confusus
  • diplostomes Bursacetabulus pelecanus
  • diplostomes Bursacetabulus macrobursus
  • endoparasitic mites Phalacrodectes punctatissimus
  • endoparasitic mites Phalacrodectes pelecani
  • endoparasitic mites Pelecanectes apunctatus
  • coccidian sporozoa Eimeria pelecani
  • Culicidae

Economic Importance for Humans: Positive

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. (Sheilds, 2002)

  • Positive Impacts
  • food
  • body parts are source of valuable material
  • research and education

Economic Importance for Humans: Negative

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. (Schreiber, 1980)

Conservation Status

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. (Nellis, 2001; Nesbitt, et al., 1978; Sheilds, 2002; Tangley, 2009)

Other Comments

Pelecanus occidentalis originates from the Greek word pelakan and the species name is Latin for "western". (Nellis, 2001)

Contributors

Victoria Scott (author), Radford University, Karen Powers (editor), Radford University, Kiersten Newtoff (editor), Radford University, Melissa Whistleman (editor), Radford University, Catherine Kent (editor), Special Projects.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

crepuscular

active at dawn and dusk

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

estuarine

an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.

female parental care

parental care is carried out by females

food

A substance that provides both nutrients and energy to a living thing.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

male parental care

parental care is carried out by males

marsh

marshes are wetland areas often dominated by grasses and reeds.

migratory

makes seasonal movements between breeding and wintering grounds

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

piscivore

an animal that mainly eats fish

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

year-round breeding

breeding takes place throughout the year

References

U.S. Fish and Wildlife Service. The California Brown Pelican recovery plan. 1448-1342-98-N015. Washington, D.C.: USFWS. 1983.

Anderson, D., J. Keith, G. Trapp, F. Gress, L. Moreno. 1989. Introduced Small Ground Predators in California Brown Pelican Colonies. Colonial Waterbirds, 12/1: 98-103.

Bartholomew, G., W. Dawsom. 1954. Temperature Regulation in Young Pelicans, Herons, and Gulls. Ecology, 35/4: 466-472.

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