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123-468: Alaska Maritime National Wildlife Refuge is well known for its abundance of seabirds . About 75 percent of Alaskan native marine birds, 15 to 30 million among 55 species, use the refuge. AMNWR also provides a nesting habitat for an estimated 40 million seabirds, representing 80 percent of all seabirds in North America . The birds congregate in "bird cities" (colonies) along the coast. Each species has

246-519: A leopard seal ) has difficulty distinguishing between a white penguin belly and the reflective water surface. The dark plumage on their backs camouflages them from above. Gentoo penguins are the fastest underwater birds in the world. They are capable of reaching speeds up to 36 km (about 22 miles) per hour while searching for food or escaping from predators. They are also able to dive to depths of 170–200 meters (about 560–660 feet). The small penguins do not usually dive deep; they catch their prey near

369-447: A murre colony. In most seabird colonies, several different species will nest on the same colony, often exhibiting some niche separation . Seabirds can nest in trees (if any are available), on the ground (with or without nests ), on cliffs, in burrows under the ground and in rocky crevices. Competition can be strong both within species and between species, with aggressive species such as sooty terns pushing less dominant species out of

492-401: A wreck . Seabirds have had a long association with both fisheries and sailors , and both have drawn benefits and disadvantages from the relationship. Fishermen have traditionally used seabirds as indicators of both fish shoals , underwater banks that might indicate fish stocks, and of potential landfall. In fact, the known association of seabirds with land was instrumental in allowing

615-454: A breeding season, though the rate the same pair recouples varies drastically. Most penguins lay two eggs in a clutch, although the two largest species, the emperor and the king penguins , lay only one. With the exception of the emperor penguin, where the male does it all, all penguins share the incubation duties. These incubation shifts can last days and even weeks as one member of the pair feeds at sea. Penguins generally only lay one brood;

738-618: A clade, the Aequornithes either became seabirds in a single transition in the Cretaceous or some lineages such as pelicans and frigatebirds adapted to sea living independently from freshwater-dwelling ancestors. In the Paleogene both pterosaurs and marine reptiles became extinct, allowing seabirds to expand ecologically. These post-extinction seas were dominated by early Procellariidae , giant penguins and two extinct families ,

861-543: A colony. Eggers from San Francisco took almost half a million eggs a year from the Farallon Islands in the mid-19th century, a period in the islands' history from which the seabird species are still recovering. Both hunting and egging continue today, although not at the levels that occurred in the past, and generally in a more controlled manner. For example, the Māori of Stewart Island / Rakiura continue to harvest

984-545: A continuous circumpolar flow only around 30 mya, on the one hand forcing the Antarctic cooling, and on the other facilitating the eastward expansion of Spheniscus to South America and eventually beyond. Despite this, there is no fossil evidence to support the idea of crown radiation from the Antarctic continent in the Paleogene, although DNA study favors such a radiation. Later, an interspersed period of slight warming

1107-486: A fashion similar to grebes and loons (using its feet to move underwater) but had a beak filled with sharp teeth. Flying Cretaceous seabirds do not exceed wingspans of two meters; any sizes were taken by piscivorous pterosaurs . While Hesperornis is not thought to have left descendants, the earliest modern seabirds also occurred in the Cretaceous, with a species called Tytthostonyx glauconiticus , which has features suggestive of Procellariiformes and Fregatidae. As

1230-451: A great deal of time in their young. Most species nest in colonies , varying in size from a few dozen birds to millions. Many species are famous for undertaking long annual migrations , crossing the equator or circumnavigating the Earth in some cases. They feed both at the ocean's surface and below it, and even on each other. Seabirds can be highly pelagic , coastal, or in some cases spend

1353-462: A group of penguins on land is a waddle , and a group of penguins in the water is a raft . Since 1871, the Latin word Pinguinus has been used in scientific classification to name the genus of the great auk ( Pinguinus impennis , meaning "plump or fat without flight feathers "), which became extinct in the mid-19th century. As confirmed by a 2004 genetic study, the genus Pinguinus belongs in

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1476-971: A large number of non-governmental organizations (including BirdLife International , the American Bird Conservancy and the Royal Society for the Protection of Birds ). This led to the Agreement on the Conservation of Albatrosses and Petrels , a legally binding treaty designed to protect these threatened species, which has been ratified by thirteen countries as of 2021 (Argentina, Australia, Brazil, Chile, Ecuador, France, New Zealand, Norway, Peru, South Africa, Spain, Uruguay, United Kingdom). Many seabirds are little studied and poorly known because they live far out at sea and breed in isolated colonies. Some seabirds, particularly

1599-570: A lineage— Eurypygimorphae —that is a sister group to the Aequornithes. Seabirds, by virtue of living in a geologically depositional environment (that is, in the sea where sediments are readily laid down), are well represented in the fossil record. They are first known to occur in the Cretaceous period, the earliest being the Hesperornithiformes , like Hesperornis regalis , a flightless loon-like seabird that could dive in

1722-424: A maritime context, pen blaen means 'front end or part, bow (of a ship), prow'. An alternative etymology links the word to Latin pinguis , which means 'fat' or 'oil'. Support for this etymology can be found in the alternative Germanic word for penguin, fettgans or 'fat-goose', and the related Dutch word vetgans . Adult male penguins are sometimes called cocks , females sometimes called hens ;

1845-587: A million birds have been recorded, both in the tropics (such as Kiritimati in the Pacific ) and in the polar latitudes (as in Antarctica ). Seabird colonies occur exclusively for the purpose of breeding; non-breeding birds will only collect together outside the breeding season in areas where prey species are densely aggregated. Seabird colonies are highly variable. Individual nesting sites can be widely spaced, as in an albatross colony, or densely packed as with

1968-485: A mostly Subantarctic distribution centred on South America ; some, however, range quite far northwards. They all lack carotenoid colouration and the former genus has a conspicuous banded head pattern; they are unique among living penguins by nesting in burrows. This group probably radiated eastwards with the Antarctic Circumpolar Current out of the ancestral range of modern penguins throughout

2091-693: A part of the year away from the sea entirely. Seabirds and humans have a long history together: They have provided food to hunters , guided fishermen to fishing stocks, and led sailors to land. Many species are currently threatened by human activities such as oil spills , nets, climate change and severe weather. Conservation efforts include the establishment of wildlife refuges and adjustments to fishing techniques. There exists no single definition of which groups, families and species are seabirds, and most definitions are in some way arbitrary. Elizabeth Shreiber and Joanna Burger, two seabird scientists, said, "The one common characteristic that all seabirds share

2214-414: A place for returning mates to reunite, and reduces the costs of prospecting for a new site. Young adults breeding for the first time usually return to their natal colony, and often nest close to where they hatched. This tendency, known as philopatry , is so strong that a study of Laysan albatrosses found that the average distance between hatching site and the site where a bird established its own territory

2337-438: A reduced capacity for powered flight and are dependent on a type of gliding called dynamic soaring (where the wind deflected by waves provides lift) as well as slope soaring. Seabirds also almost always have webbed feet , to aid movement on the surface as well as assisting diving in some species. The Procellariiformes are unusual among birds in having a strong sense of smell , which is used to find widely distributed food in

2460-535: A region around 2,000 km south of the equator 35  mya , during the Late Eocene , a climate decidedly warmer than today. The word penguin first appears in literature at the end of the 16th century as a synonym for the great auk . When European explorers discovered what are today known as penguins in the Southern Hemisphere, they noticed their similar appearance to the great auk of

2583-461: A smaller layer of air (compared to other diving birds) but otherwise soak up water. This allows them to swim without fighting the buoyancy that retaining air in the feathers causes, yet retain enough air to prevent the bird losing excessive heat through contact with water. The plumage of most seabirds is less colourful than that of land birds, restricted in the main to variations of black, white or grey. A few species sport colourful plumes (such as

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2706-575: A source of increasing concern to conservationists. The bycatch of seabirds entangled in nets or hooked on fishing lines has had a big impact on seabird numbers; for example, an estimated 100,000 albatrosses are hooked and drown each year on tuna lines set out by long-line fisheries. Overall, many hundreds of thousands of birds are trapped and killed each year, a source of concern for some of the rarest species (for example, only about 2,000 short-tailed albatrosses are known to still exist). Seabirds are also thought to suffer when overfishing occurs. Changes to

2829-519: A specialized nesting site (rock ledge, crevice, boulder rubble, pinnacle, or burrow). Other animals present in this refuge include caribou , sea lions , bears , coyotes , seals , Canada lynx , beavers , foxes , muskrats , wolf packs, moose , walrus , river otters , marten , whales , Dall sheep and sea otters . The administrative headquarters and visitor center are located in Homer, Alaska . In 1968, Simeonof National Wildlife Refuge, part of

2952-408: A spiny tongue and powerful jaws to grip slippery prey. They spend about half of their lives on land and the other half in the sea. The largest living species is the emperor penguin ( Aptenodytes forsteri ): on average, adults are about 1.1 m (3 ft 7 in) tall and weigh 35 kg (77 lb). The smallest penguin species is the little blue penguin ( Eudyptula minor ), also known as

3075-403: A vast ocean, and help distinguish familiar nest odours from unfamiliar ones. Salt glands are used by seabirds to deal with the salt they ingest by drinking and feeding (particularly on crustaceans ), and to help them osmoregulate . The excretions from these glands (which are positioned in the head of the birds, emerging from the nasal cavity ) are almost pure sodium chloride . With

3198-400: A very variable prey source); this may be a reason why it arises more frequently in seabirds. There are other possible advantages: colonies may act as information centres, where seabirds returning to the sea to forage can find out where prey is by studying returning individuals of the same species. There are disadvantages to colonial life, particularly the spread of disease. Colonies also attract

3321-458: A year, unless they lose the first (with a few exceptions, like the Cassin's auklet ), and many species (like the tubenoses and sulids ) will only lay one egg a year. Care of young is protracted, extending for as long as six months, among the longest for birds. For example, once common guillemot chicks fledge , they remain with the male parent for several months at sea. The frigatebirds have

3444-407: Is energetically inefficient in warmer waters. With their poor flying ability, many wing-propelled pursuit divers are more limited in their foraging range than other guilds. Gannets , boobies , tropicbirds , some terns, and brown pelicans all engage in plunge diving, taking fast-moving prey by diving into the water from the flight. Plunge diving allows birds to use the energy from the momentum of

3567-642: Is inconclusive. Some plunge divers (as well as some surface feeders) are dependent on dolphins and tuna to push shoaling fish up towards the surface. This catch-all category refers to other seabird strategies that involve the next trophic level up. Kleptoparasites are seabirds that make a part of their living stealing food of other seabirds. Most famously, frigatebirds and skuas engage in this behaviour, although gulls, terns and other species will steal food opportunistically. The nocturnal nesting behaviour of some seabirds has been interpreted as arising due to pressure from this aerial piracy. Kleptoparasitism

3690-460: Is much greater than in air). The emperor penguin has a maximum feather density of about nine feathers per square centimeter which is actually much lower than other birds that live in Antarctic environments. However, they have been identified as having at least four different types of feather: in addition to the traditional feather, the emperor has afterfeathers , plumules , and filoplumes . The afterfeathers are downy plumes that attach directly to

3813-545: Is not thought to play a significant part of the diet of any species, and is instead a supplement to food obtained by hunting. A study of great frigatebirds stealing from masked boobies estimated that the frigatebirds could at most obtain 40% of the food they needed, and on average obtained only 5%. Many species of gull will feed on seabird and sea mammal carrion when the opportunity arises, as will giant petrels . Some species of albatross also engage in scavenging: an analysis of regurgitated squid beaks has shown that many of

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3936-402: Is often a problem as well—visitors, even well-meaning tourists, can flush brooding adults off a colony, leaving chicks and eggs vulnerable to predators. The build-up of toxins and pollutants in seabirds is also a concern. Seabirds, being apex predators , suffered from the ravages of the insecticide DDT until it was banned; DDT was implicated, for example, in embryo development problems and

4059-457: Is or includes the paleeudyptines as recognized today – occurred on most Antarctic and Subantarctic coasts. Size plasticity was significant at this initial stage of radiation : on Seymour Island , Antarctica, for example, around 10 known species of penguins ranging in size from medium to large apparently coexisted some 35 mya during the Priabonian (Late Eocene). It is not known whether

4182-463: Is punished for killing an albatross by having to wear its corpse around his neck. Sailors did, however, consider it unlucky to touch a storm petrel, especially one that landed on the ship. Penguin For prehistoric genera, see List of penguins#Fossil genera Penguins are a group of aquatic flightless birds from the family Spheniscidae ( / s f ɪ ˈ n ɪ s ɪ d iː , - d aɪ / ) of

4305-489: Is some evidence of this, the effects of seabirds are considered smaller than that of marine mammals and predatory fish (like tuna ). Some seabird species have benefited from fisheries, particularly from discarded fish and offal . These discards compose 30% of the food of seabirds in the North Sea , for example, and compose up to 70% of the total food of some seabird populations. This can have other impacts; for example,

4428-489: Is sometimes called " higher waterbirds " to distinguish them from the more ancient waterfowl . This group contains such birds as storks , rails , and the seabirds , with the possible exception of the Charadriiformes . Inside this group, penguin relationships are far less clear. Depending on the analysis and dataset, a close relationship to Ciconiiformes or to Procellariiformes has been suggested. Some think

4551-719: Is that they feed in saltwater ; but, as seems to be true with any statement in biology, some do not." However, by convention all of the Sphenisciformes (penguins) and Procellariiformes ( albatrosses and petrels ), all of the Suliformes ( gannets and cormorants ) except the darters , and some of the Charadriiformes (the gulls , skuas , terns , auks and skimmers ) are classified as seabirds. The phalaropes are usually included as well, since although they are waders ("shorebirds" in North America), two of

4674-589: Is the skimmer , which has a unique fishing method: flying along the surface with the lower mandible in the water—this shuts automatically when the bill touches something in the water. The skimmer's bill reflects its unusual lifestyle, with the lower mandible uniquely being longer than the upper one. Surface feeders that swim often have unique bills as well, adapted for their specific prey. Prions have special bills with filters called lamellae to filter out plankton from mouthfuls of water, and many albatrosses and petrels have hooked bills to snatch fast-moving prey. On

4797-448: Is the deepest diver of the shearwaters, having been recorded diving below 70 metres (230 ft). Some albatross species are also capable of limited diving, with light-mantled sooty albatrosses holding the record at 12 metres (40 ft). Of all the wing-propelled pursuit divers, the most efficient in the air are the albatrosses, and they are also the poorest divers. This is the dominant guild in polar and subpolar environments, but it

4920-404: Is used by parents and chicks to locate one another in crowded colonies . Their eyes are adapted for underwater vision and are their primary means of locating prey and avoiding predators; in air it has been suggested that they are nearsighted , although research has not supported this hypothesis. Penguins have a thick layer of insulating feathers that keeps them warm in water (heat loss in water

5043-643: Is well-researched, many prehistoric forms are not fully described . Some seminal articles about the evolutionary history of penguins have been published since 2005. The basal penguins lived around the time of the Cretaceous–Paleogene extinction event in the general area of southern New Zealand and Byrd Land , Antarctica. Due to plate tectonics , these areas were at that time less than 1,500 kilometres (930 mi) apart rather than 4,000 kilometres (2,500 mi). The most recent common ancestor of penguins and Procellariiformes can be roughly dated to

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5166-776: The Oxford English Dictionary , the American Heritage Dictionary , the Century Dictionary and Merriam-Webster , on the basis that the name was originally applied to the great auk, either because it was found on White Head Island ( Welsh : Pen Gwyn ) in Newfoundland, or because it had white circles around its eyes (though the head was black). However, the Welsh word pen can also be used to mean 'front' and, in

5289-472: The Antarctic Peninsula and Patagonia have not yielded Paleogene fossils of the subfamily. Also, the earliest spheniscine lineages are those with the most southern distribution. The genus Aptenodytes appears to be the basalmost divergence among living penguins. They have bright yellow-orange neck, breast, and bill patches; incubate by placing their eggs on their feet, and when they hatch

5412-646: The Campanian – Maastrichtian boundary, around 70–68 mya. The oldest known fossil penguin species is Waimanu manneringi , which lived 62 mya in New Zealand. While they were not as well-adapted to aquatic life as modern penguins, Waimanu were flightless, with short wings adapted for deep diving. They swam on the surface using mainly their feet, but the wings were – as opposed to most other diving birds (both living and extinct) – already adapting to underwater locomotion. Perudyptes from northern Peru

5535-671: The Chattian (Late Oligocene), starting approximately 28 mya. While the two genera separated during this time, the present-day diversity is the result of a Pliocene radiation, taking place some 4–2 mya. The Megadyptes – Eudyptes clade occurs at similar latitudes (though not as far north as the Galápagos penguin ), has its highest diversity in the New Zealand region, and represents a westward dispersal. They are characterized by hairy yellow ornamental head feathers; their bills are at least partly red. These two genera diverged apparently in

5658-623: The Northern Hemisphere and named them after this bird, although they are not closely related. The etymology of the word penguin is still debated. The English word is not apparently of French , Breton or Spanish origin (the latter two are attributed to the French word pingouin ), but first appears in English or Dutch. Some dictionaries suggest a derivation from Welsh pen , 'head' and gwyn , 'white', including

5781-715: The Pelagornithidae and the Plotopteridae (a group of large seabirds that looked like the penguins). Modern genera began their wide radiation in the Miocene , although the genus Puffinus (which includes today's Manx shearwater and sooty shearwater ) might date back to the Oligocene . Within the Charadriiformes, the gulls and allies ( Lari ) became seabirds in the late Eocene, and then waders in

5904-703: The Polynesians to locate tiny landmasses in the Pacific. Seabirds have provided food for fishermen away from home, as well as bait. Famously, tethered cormorants have been used to catch fish directly. Indirectly, fisheries have also benefited from guano from colonies of seabirds acting as fertilizer for the surrounding seas. Negative effects on fisheries are mostly restricted to raiding by birds on aquaculture , although long-lining fisheries also have to deal with bait stealing. There have been claims of prey depletion by seabirds of fishery stocks, and while there

6027-455: The marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution , as the same environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period , and modern seabird families emerged in the Paleogene . Seabirds generally live longer, breed later and have fewer young than other birds, but they invest

6150-677: The millinery trade reached industrial levels. Muttonbirding (harvesting shearwater chicks) developed as important industries in both New Zealand and Tasmania, and the name of one species, the providence petrel , is derived from its seemingly miraculous arrival on Norfolk Island where it provided a windfall for starving European settlers. In the Falkland Islands , hundreds of thousands of penguins were harvested for their oil each year. Seabird eggs have also long been an important source of food for sailors undertaking long sea voyages, as well as being taken when settlements grow in areas near

6273-630: The order Sphenisciformes ( / s f ɪ ˈ n ɪ s ə f ɔːr m iː z / ). They live almost exclusively in the Southern Hemisphere : only one species , the Galápagos penguin , is found north of the Equator . Highly adapted for life in the ocean water, penguins have countershaded dark and white plumage and flippers for swimming. Most penguins feed on krill , fish , squid and other forms of sea life which they catch with their bills and swallow whole while swimming. A penguin has

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6396-494: The phylogenetic taxon Spheniscidae to what here is referred to as Spheniscinae. Furthermore, they restrict the phylogenetic taxon Sphenisciformes to flightless taxa, and establish the phylogenetic taxon Pansphenisciformes as equivalent to the Linnean taxon Sphenisciformes, i.e., including any flying basal "proto-penguins" to be discovered eventually. Given that neither the relationships of the penguin subfamilies to each other nor

6519-419: The razorbill (an Atlantic auk) requires 64% more energy to fly than a petrel of equivalent size. Many shearwaters are intermediate between the two, having longer wings than typical wing-propelled divers but heavier wing loadings than the other surface-feeding procellariids , leaving them capable of diving to considerable depths while still being efficient long-distance travellers. The short-tailed shearwater

6642-481: The shearwaters and gadfly petrels). Surface feeders in flight include some of the most acrobatic of seabirds, which either snatch morsels from the water (as do frigate-birds and some terns), or "walk", pattering and hovering on the water's surface, as some of the storm-petrels do. Many of these do not ever land in the water, and some, such as the frigatebirds, have difficulty getting airborne again should they do so. Another seabird family that does not land while feeding

6765-579: The "heterothermic loophole" that penguins utilize in order to survive in Antarctica. All extant penguins, even those that live in warmer climates, have a counter-current heat exchanger called the humeral plexus. The flippers of penguins have at least three branches of the axillary artery, which allows cold blood to be heated by blood that has already been warmed and limits heat loss from the flippers. This system allows penguins to efficiently use their body heat and explains why such small animals can survive in

6888-925: The Alaska Maritime National Wildlife Refuge, was designated as a National Natural Landmark by the National Park Service. The refuge is divided into five units. Clockwise around Alaska, starting in the southeast, their component territories include: Includes most of the land area of the Aleutian Islands , from Unimak in the east to Attu in the west: Near Islands , Rat Islands , Delarof Islands , Andreanof Islands , Islands of Four Mountains , Fox Islands , and Krenitzin Islands Seabird Seabirds (also known as marine birds ) are birds that are adapted to life within

7011-469: The Antarctic mainland, are unlikely to find anything to eat around their breeding sites. The marbled murrelet nests inland in old growth forest , seeking huge conifers with large branches to nest on. Other species, such as the California gull , nest and feed inland on lakes, and then move to the coasts in the winter. Some cormorant, pelican , gull and tern species have individuals that never visit

7134-582: The Arctic tern; birds that nest in New Zealand and Chile and spend the northern summer feeding in the North Pacific off Japan, Alaska and California, an annual round trip of 64,000 kilometres (40,000 mi). Other species also migrate shorter distances away from the breeding sites, their distribution at sea determined by the availability of food. If oceanic conditions are unsuitable, seabirds will emigrate to more productive areas, sometimes permanently if

7257-667: The Austral summer in Antarctica. Other species also undertake trans-equatorial trips, both from the north to the south, and from south to north. The population of elegant terns , which nest off Baja California , splits after the breeding season with some birds travelling north to the Central Coast of California and some travelling as far south as Peru and Chile to feed in the Humboldt Current . The sooty shearwater undertakes an annual migration cycle that rivals that of

7380-526: The Middle Miocene ( Langhian , roughly 15–14 mya), although the living species of Eudyptes are the product of a later radiation, stretching from about the late Tortonian (Late Miocene, 8 mya) to the end of the Pliocene. The geographical and temporal pattern of spheniscine evolution corresponds closely to two episodes of global cooling documented in the paleoclimatic record . The emergence of

7503-542: The Spheniscinae lies probably in the latest Paleogene and, geographically, it must have been much the same as the general area in which the order evolved: the oceans between the Australia-New Zealand region and the Antarctic. Presumably diverging from other penguins around 40 mya, it seems that the Spheniscinae were for quite some time limited to their ancestral area, as the well-researched deposits of

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7626-683: The Spheniscinae, as Aptenodytes ' autapomorphies are, in most cases, fairly pronounced adaptations related to that genus' extreme habitat conditions. As the former genus, Pygoscelis seems to have diverged during the Bartonian, but the range expansion and radiation that led to the present-day diversity probably did not occur until much later; around the Burdigalian stage of the Early Miocene , roughly 20–15 mya. The genera Spheniscus and Eudyptula contain species with

7749-542: The Subantarctic lineage at the end of the Bartonian corresponds with the onset of the slow period of cooling that eventually led to the ice ages some 35 million years later. With habitat on the Antarctic coasts declining, by the Priabonian more hospitable conditions for most penguins existed in the Subantarctic regions rather than in Antarctica itself. Notably, the cold Antarctic Circumpolar Current also started as

7872-556: The UK was the Scottish Seabird Centre , near the important bird sanctuaries on Bass Rock , Fidra and the surrounding islands. The area is home to huge colonies of gannets, puffins , skuas and other seabirds. The centre allows visitors to watch live video from the islands as well as learn about the threats the birds face and how we can protect them, and has helped to significantly raise the profile of seabird conservation in

7995-480: The UK. Seabird tourism can provide income for coastal communities as well as raise the profile of seabird conservation, although it needs to be managed to ensure it does not harm the colonies and nesting birds. For example, the northern royal albatross colony at Taiaroa Head in New Zealand attracts 40,000 visitors a year. The plight of albatross and large seabirds, as well as other marine creatures, being taken as bycatch by long-line fisheries, has been addressed by

8118-533: The air. In the water, however, penguins are astonishingly agile. Penguins' swimming looks very similar to birds' flight in the air. Within the smooth plumage a layer of air is preserved, ensuring buoyancy. The air layer also helps insulate the birds in cold waters. On land, penguins use their tails and wings to maintain balance for their upright stance. All penguins are countershaded for camouflage – that is, they have black backs and wings with white fronts. A predator looking up from below (such as an orca or

8241-467: The albatrosses and gulls, are more well known to humans. The albatross has been described as "the most legendary of birds", and have a variety of myths and legends associated with them. While it is widely considered unlucky to harm them, the notion that sailors believed that is a myth that derives from Samuel Taylor Coleridge 's famous poem, " The Rime of the Ancient Mariner ", in which a sailor

8364-452: The attention of predators , principally other birds, and many species attend their colonies nocturnally to avoid predation. Birds from different colonies often forage in different areas to avoid competition. Like many birds, seabirds often migrate after the breeding season . Of these, the trip taken by the Arctic tern is the farthest of any bird, crossing the equator in order to spend

8487-454: The bird is young. After fledging, juvenile birds often disperse further than adults, and to different areas, so are commonly sighted far from a species' normal range. Some species, such as the auks, do not have a concerted migration effort, but drift southwards as the winter approaches. Other species, such as some of the storm petrels, diving petrels and cormorants, never disperse at all, staying near their breeding colonies year round. While

8610-421: The chicks are almost naked. This genus has a distribution centred on the Antarctic coasts and barely extends to some Subantarctic islands today. Pygoscelis contains species with a fairly simple black-and-white head pattern; their distribution is intermediate, centred on Antarctic coasts but extending somewhat northwards from there. In external morphology , these apparently still resemble the common ancestor of

8733-486: The chicks of the sooty shearwater as they have done for centuries, using traditional stewardship, kaitiakitanga , to manage the harvest, but now also work with the University of Otago in studying the populations. In Greenland , however, uncontrolled hunting is pushing many species into steep decline. Other human factors have led to declines and even extinctions in seabird populations and species. Of these, perhaps

8856-453: The definition of seabirds suggests that the birds in question spend their lives on the ocean, many seabird families have many species that spend some or even most of their lives inland away from the sea. Most strikingly, many species breed tens, hundreds or even thousands of miles inland. Some of these species still return to the ocean to feed; for example, the snow petrel , the nests of which have been found 480 kilometres (300 mi) inland on

8979-451: The disease have scarred digestive tracts from ingesting plastic waste . "When birds ingest small pieces of plastic, they found, it inflames the digestive tract. Over time, the persistent inflammation causes tissues to become scarred and disfigured, affecting digestion, growth and survival." The threats faced by seabirds have not gone unnoticed by scientists or the conservation movement . As early as 1903, U.S. President Theodore Roosevelt

9102-456: The dive to combat natural buoyancy (caused by air trapped in plumage), and thus uses less energy than the dedicated pursuit divers, allowing them to utilise more widely distributed food resources, for example, in impoverished tropical seas. In general, this is the most specialised method of hunting employed by seabirds; other non-specialists (such as gulls and skuas) may employ it but do so with less skill and from lower heights. In brown pelicans,

9225-413: The earliest instances known is in southern Chile, where archaeological excavations in middens has shown hunting of albatrosses, cormorants and shearwaters from 5000 BP. This pressure has led to some species becoming extinct in many places; in particular, at least 20 species of an original 29 no longer breed on Easter Island . In the 19th century, the hunting of seabirds for fat deposits and feathers for

9348-517: The emergence of another morphotype in the same area, the similarly sized but more gracile Palaeospheniscinae , as well as the radiation that gave rise to the current biodiversity of penguins. Modern penguins constitute two undisputed clades and another two more basal genera with more ambiguous relationships. To help resolve the evolution of this order , 19 high-coverage genomes that, together with two previously published genomes, encompass all extant penguin species have been sequenced. The origin of

9471-544: The end of the Paleogene , around 25 mya. Their decline and disappearance coincided with the spread of the Squalodontidae and other primitive, fish-eating toothed whales , which competed with them for food and were ultimately more successful. A new lineage, the Paraptenodytes , which includes smaller and stout-legged forms, had already arisen in southernmost South America by that time. The early Neogene saw

9594-402: The exception is the little penguin, which can raise two or three broods in a season. Penguin eggs are smaller than any other bird species when compared proportionally to the weight of the parent birds; at 52 g (2 oz), the little penguin egg is 4.7% of its mothers' weight, and the 450 g (1 lb) emperor penguin egg is 2.3%. The relatively thick shell forms between 10 and 16% of

9717-404: The exception of the cormorants and some terns, and in common with most other birds, all seabirds have waterproof plumage . However, compared to land birds, they have far more feathers protecting their bodies. This dense plumage is better able to protect the bird from getting wet, and cold is kept out by a dense layer of down feathers . The cormorants possess a layer of unique feathers that retain

9840-475: The extreme cold of the Antarctic winter, the females are at sea fishing for food, leaving the males to brave the weather by themselves. They often huddle together to keep warm and rotate positions to make sure that each penguin gets a turn in the centre of the heat pack. Calculations of the heat loss and retention ability of marine endotherms suggest that most extant penguins are too small to survive in such cold environments. In 2007, Thomas and Fordyce wrote about

9963-472: The extreme cold. They can drink salt water because their supraorbital gland filters excess salt from the bloodstream. The salt is excreted in a concentrated fluid from the nasal passages. The great auk of the Northern Hemisphere, now extinct, was superficially similar to penguins, and the word penguin was originally used for that bird centuries ago. They are only distantly related to

10086-442: The fairy penguin, which stands around 30–33 cm (12–13 in) tall and weighs 1.2–1.3 kg (2.6–2.9 lb). Today, larger penguins generally inhabit colder regions, and smaller penguins inhabit regions with temperate or tropical climates . Some prehistoric penguin species were enormous: as tall or heavy as an adult human. There was a great diversity of species in subantarctic regions, and at least one giant species in

10209-400: The family of the auks (Alcidae), within the order of the Charadriiformes . The birds currently known as penguins were discovered later and were so named by sailors because of their physical resemblance to the great auk. Despite this resemblance, however, they are not auks, and are not closely related to the great auk. They do not belong in the genus Pinguinus , and are not classified in

10332-676: The feathers resist abrasion. Seabirds evolved to exploit different food resources in the world's seas and oceans, and to a great extent, their physiology and behaviour have been shaped by their diet . These evolutionary forces have often caused species in different families and even orders to evolve similar strategies and adaptations to the same problems, leading to remarkable convergent evolution , such as that between auks and penguins. There are four basic feeding strategies, or ecological guilds, for feeding at sea: surface feeding, pursuit diving, plunge-diving, and predation of higher vertebrates ; within these guilds, there are multiple variations on

10455-475: The first time in over a hundred years. Seabird mortality caused by long-line fisheries can be greatly reduced by techniques such as setting long-line bait at night, dying the bait blue, setting the bait underwater, increasing the amount of weight on lines and by using bird scarers, and their deployment is increasingly required by many national fishing fleets. One of the Millennium Projects in

10578-478: The frequency of breeding failures due to unfavourable marine conditions, and the relative lack of predation compared to that of land-living birds. Because of the greater investment in raising the young and because foraging for food may occur far from the nest site, in all seabird species except the phalaropes, both parents participate in caring for the young, and pairs are typically at least seasonally monogamous . Many species, such as gulls, auks and penguins, retain

10701-468: The longest period of parental care of any bird except a few raptors and the southern ground hornbill , with each chick fledging after four to six months and continued assistance after that for up to fourteen months. Due to the extended period of care, breeding occurs every two years rather than annually for some species. This life-history strategy has probably evolved both in response to the challenges of living at sea (collecting widely scattered prey items),

10824-414: The main feathers and were once believed to account for the bird's ability to conserve heat when under water; the plumules are small down feathers that attach directly to the skin, and are much more dense in penguins than other birds; lastly the filoplumes are small (less than 1 cm long) naked shafts that end in a splay of fibers— filoplumes were believed to give flying birds a sense of where their plumage

10947-408: The marine ecosystems caused by dredging, which alters the biodiversity of the seafloor, can also have a negative impact. The hunting of seabirds and the collecting of seabird eggs have contributed to the declines of many species, and the extinction of several, including the great auk and the spectacled cormorant . Seabirds have been hunted for food by coastal peoples throughout history—one of

11070-580: The middle Miocene ( Langhian ). The highest diversity of seabirds apparently existed during the Late Miocene and the Pliocene . At the end of the latter, the oceanic food web had undergone a period of upheaval due to extinction of considerable numbers of marine species; subsequently, the spread of marine mammals seems to have prevented seabirds from reaching their erstwhile diversity. Seabirds have made numerous adaptations to living on and feeding in

11193-490: The most desirable nesting spaces. The tropical Bonin petrel nests during the winter to avoid competition with the more aggressive wedge-tailed shearwater . When the seasons overlap, the wedge-tailed shearwaters will kill young Bonin petrels in order to use their burrows. Many seabirds show remarkable site fidelity , returning to the same burrow, nest or site for many years, and they will defend that site from rivals with great vigour. This increases breeding success, provides

11316-607: The most part breed in large colonies, the exceptions being the yellow-eyed and Fiordland species; these colonies may range in size from as few as 100 pairs for gentoo penguins to several hundred thousand in the case of king, macaroni and chinstrap penguins. Living in colonies results in a high level of social interaction between birds, which has led to a large repertoire of visual as well as vocal displays in all penguin species. Agonistic displays are those intended to confront or drive off, or alternately appease and avoid conflict with, other individuals. Penguins form monogamous pairs for

11439-552: The most serious are introduced species . Seabirds, breeding predominantly on small isolated islands, are vulnerable to predators because they have lost many behaviours associated with defence from predators. Feral cats can take seabirds as large as albatrosses, and many introduced rodents, such as the Pacific rat , take eggs hidden in burrows. Introduced goats, cattle, rabbits and other herbivores can create problems, particularly when species need vegetation to protect or shade their young. The disturbance of breeding colonies by humans

11562-428: The ocean lead to decreased availability of food and colonies are more often flooded as a consequence of sea level rise and extreme rainfall events. Heat stress from extreme temperatures is an additional threat. Some seabirds have used changing wind patterns to forage further and more efficiently. In 2023, plasticosis , a new disease caused solely by plastics, was discovered in seabirds. The birds identified as having

11685-841: The other hand, most gulls are versatile and opportunistic feeders who will eat a wide variety of prey, both at sea and on land. Pursuit diving exerts greater pressures (both evolutionary and physiological) on seabirds, but the reward is a greater area in which to feed than is available to surface feeders. Underwater propulsion is provided by wings (as used by penguins, auks, diving petrels and some other species of petrel) or feet (as used by cormorants, grebes , loons and several types of fish-eating ducks ). Wing-propelled divers are generally faster than foot-propelled divers. The use of wings or feet for diving has limited their utility in other situations: loons and grebes walk with extreme difficulty (if at all), penguins cannot fly, and auks have sacrificed flight efficiency in favour of diving. For example,

11808-652: The palaeeudyptines constitute a monophyletic lineage, or whether gigantism was evolved independently in a restricted Palaeeudyptinae and the Anthropornithinae – whether they were considered valid, or whether there was a wide size range present in the Palaeeudyptinae as delimited (i.e., including Anthropornis nordenskjoeldi ). The oldest well-described giant penguin, the 5-foot (1.5 m)-tall Icadyptes salasi , existed as far north as northern Peru about 36 mya. Gigantic penguins had disappeared by

11931-473: The penguin-like plotopterids (usually considered relatives of cormorants and anhingas ) may actually be a sister group of the penguins and those penguins may have ultimately shared a common ancestor with the Pelecaniformes and consequently would have to be included in that order, or that the plotopterids were not as close to other pelecaniforms as generally assumed, which would necessitate splitting

12054-408: The penguins, but are an example of convergent evolution . Around one in 50,000 penguins (of most species) are born with brown rather than black plumage. These are called isabelline penguins. Isabellinism is different from albinism. Isabelline penguins tend to live shorter lives than normal penguins, as they are not well-camouflaged against the deep and are often passed over as mates. Penguins for

12177-594: The penguins, puffins have a white chest, black back and short stubby wings providing excellent swimming ability in icy water. But, unlike penguins, puffins can fly, as flightless birds would not survive alongside land-based predators such as polar bears and foxes; there are no such predators in the Antarctic. Their similarities indicate that similar environments, although at great distances, can result in similar evolutionary developments, i.e. convergent evolution . Penguins are superbly adapted to aquatic life. Their wings have evolved to become flippers, useless for flight in

12300-400: The placement of the penguins in the avian phylogeny is presently resolved, this is confusing, so the established Linnean system is followed here. The number of penguin species is typically listed as between seventeen and nineteen. The International Ornithologists' Union recognizes six genera and eighteen species: Although the evolutionary and biogeographic history of Sphenisciformes

12423-437: The removal of exotic invaders from increasingly large islands. Feral cats have been removed from Ascension Island , Arctic foxes from many islands in the Aleutian Islands , and rats from Campbell Island . The removal of these introduced species has led to increases in numbers of species under pressure and even the return of extirpated ones. After the removal of cats from Ascension Island, seabirds began to nest there again for

12546-518: The same family and order as the great auk. They were classified in 1831 by Charles Lucien Bonaparte in several distinct genera within the family Spheniscidae and order Sphenisciformes . The family name of Spheniscidae was given by Charles Lucien Bonaparte from the genus Spheniscus , the name of that genus comes from the Greek word σφήν sphēn " wedge " used for the shape of an African penguin 's swimming flippers. Some recent sources apply

12669-465: The same mate for several seasons, and many petrel species mate for life. Albatrosses and procellariids , which mate for life, take many years to form a pair bond before they breed, and the albatrosses have an elaborate breeding dance that is part of pair-bond formation. Ninety-five percent of seabirds are colonial, and seabird colonies are among the largest bird colonies in the world, providing one of Earth's great wildlife spectacles. Colonies of over

12792-653: The sea at all, spending their lives on lakes, rivers, swamps and, in the case of some of the gulls, cities and agricultural land. In these cases, it is thought that these terrestrial or freshwater birds evolved from marine ancestors. Some seabirds, principally those that nest in tundra , as skuas and phalaropes do, will migrate over land as well. The more marine species, such as petrels, auks and gannets , are more restricted in their habits, but are occasionally seen inland as vagrants. This most commonly happens to young inexperienced birds, but can happen in great numbers to exhausted adults after large storms , an event known as

12915-507: The sea's edge (coast), but are also not treated as seabirds. Sea eagles and other fish-eating birds of prey are also typically excluded, however tied to marine environments they may be. German ornithologist Gerald Mayr defined the "core waterbird" clade Aequornithes in 2010. This lineage gives rise to the Gaviiformes , Sphenisciformes , Procellariiformes, Ciconiiformes , Suliformes and Pelecaniformes . The tropicbirds are part of

13038-407: The sea. Wing morphology has been shaped by the niche an individual species or family has evolved , so that looking at a wing's shape and loading can tell a scientist about its life feeding behaviour. Longer wings and low wing loading are typical of more pelagic species, while diving species have shorter wings. Species such as the wandering albatross , which forage over huge areas of sea, have

13161-416: The skewed sex ratio of western gulls in southern California. Oil spills are also a threat to seabirds: the oil is toxic, and bird feathers become saturated by the oil, causing them to lose their waterproofing. Oil pollution in particular threatens species with restricted ranges or already depressed populations. Climate change mainly affect seabirds via changes to their habitat : various processes in

13284-432: The skills of plunge-diving take several years to fully develop—once mature, they can dive from 20 m (66 ft) above the water's surface, shifting the body before impact to avoid injury. It may be that plunge divers are restricted in their hunting grounds to clear waters that afford a view of their prey from the air. While they are the dominant guild in the tropics, the link between plunge diving and water clarity

13407-496: The spread of the northern fulmar through the United Kingdom is attributed in part to the availability of discards. Discards generally benefit surface feeders, such as gannets and petrels, to the detriment of pursuit divers like penguins and guillemots, which can get entangled in the nets. Fisheries also have negative effects on seabirds, and these effects, particularly on the long-lived and slow-breeding albatrosses, are

13530-695: The squid eaten are too large to have been caught alive, and include mid-water species likely to be beyond the reach of albatrosses. Some species will also feed on other seabirds; for example, gulls, skuas and pelicans will often take eggs, chicks and even small adult seabirds from nesting colonies, while the giant petrels can kill prey up to the size of small penguins and seal pups. Seabirds' life histories are dramatically different from those of land birds. In general, they are K-selected , live much longer (anywhere between twenty and sixty years), delay breeding for longer (for up to ten years), and invest more effort into fewer young. Most species will only have one clutch

13653-544: The strong adaptive autapomorphies of the Sphenisciformes; a sometimes perceived fairly close relationship between penguins and grebes is almost certainly an error based on both groups' strong diving adaptations, which are homoplasies . On the other hand, different DNA sequence datasets do not agree in detail with each other either. What seems clear is that penguins belong to a clade of Neoaves (living birds except for paleognaths and fowl ) that comprises what

13776-641: The surface in dives that normally last only one or two minutes. Larger penguins can dive deep in case of need. Emperor penguins are the world's deepest-diving birds. They can dive to depths of approximately 550 meters (1,800 feet) while searching for food. Penguins either waddle on their feet or slide on their bellies across the snow while using their feet to propel and steer themselves, a movement called "tobogganing", which conserves energy while moving quickly. They also jump with both feet together if they want to move more quickly or cross steep or rocky terrain. Penguins have an average sense of hearing for birds; this

13899-495: The theme. Many seabirds feed on the ocean's surface, as the action of marine currents often concentrates food such as krill , forage fish , squid , or other prey items within reach of a dipped head. Surface feeding itself can be broken up into two different approaches, surface feeding while flying (for example as practiced by gadfly petrels , frigatebirds , and storm petrels ), and surface feeding while swimming (examples of which are practiced by gulls , fulmars , many of

14022-491: The three species ( Red and Red-necked ) are oceanic for nine months of the year, crossing the equator to feed pelagically. Loons and grebes , which nest on lakes but winter at sea, are usually categorized as water birds, not seabirds. Although there are a number of sea ducks in the family Anatidae that are truly marine in the winter, by convention they are usually excluded from the seabird grouping. Many waders (or shorebirds) and herons are also highly marine, living on

14145-440: The traditional Pelecaniformes into three. A 2014 analysis of whole genomes of 48 representative bird species has concluded that penguins are the sister group of Procellariiformes, from which they diverged about 60 million years ago (95% CI, 56.8–62.7). The distantly related Puffins , which live in the North Pacific and North Atlantic, developed similar characteristics to survive in the Arctic and sub-Arctic environments. Like

14268-499: The tropicbirds and some penguins), but most of the colour in seabirds appears in the bills and legs. The plumage of seabirds is thought in many cases to be for camouflage , both defensive (the colour of US Navy battleships is the same as that of Antarctic prions , and in both cases it reduces visibility at sea) and aggressive (the white underside possessed by many seabirds helps hide them from prey below). The usually black wing tips help prevent wear, as they contain melanins that help

14391-491: The weight of a penguin egg, presumably to reduce the effects of dehydration and to minimize the risk of breakage in an adverse nesting environment. The yolk, too, is large and comprises 22–31% of the egg. Some yolk often remains when a chick is born, and is thought to help sustain the chick if the parents are delayed in returning with food. When emperor penguin mothers lose a chick, they sometimes attempt to "steal" another mother's chick, usually unsuccessfully as other females in

14514-584: Was 22 metres (72 ft); another study, this time on Cory's shearwaters nesting near Corsica , found that of nine out of 61 male chicks that returned to breed at their natal colony bred in the burrow they were raised in, and two actually bred with their own mother. Colonies are usually situated on islands, cliffs or headlands, which land mammals have difficulty accessing. This is thought to provide protection to seabirds, which are often very clumsy on land. Coloniality often arises in types of bird that do not defend feeding territories (such as swifts , which have

14637-417: Was and whether or not it needed preening, so their presence in penguins may seem inconsistent, but penguins also preen extensively. The emperor penguin has the largest body mass of all penguins, which further reduces relative surface area and heat loss. They also are able to control blood flow to their extremities, reducing the amount of blood that gets cold, but still keeping the extremities from freezing. In

14760-679: Was convinced of the need to declare Pelican Island in Florida a National Wildlife Refuge to protect the bird colonies (including the nesting brown pelicans ), and in 1909 he protected the Farallon Islands. Today many important seabird colonies are given some measure of protection, from Heron Island in Australia to Triangle Island in British Columbia. Island restoration techniques, pioneered by New Zealand, enable

14883-645: Was dated to 42 mya. An unnamed fossil from Argentina proves that, by the Bartonian (Middle Eocene), some 39–38 mya, primitive penguins had spread to South America and were in the process of expanding into Atlantic waters. During the Late Eocene and the Early Oligocene (40–30 mya), some lineages of gigantic penguins existed. Nordenskjoeld's giant penguin was the tallest, growing nearly 1.80 meters (5.9 feet) tall. The New Zealand giant penguin

15006-770: Was ended by the Middle Miocene Climate Transition , a sharp drop in global average temperature from 14 to 12 mya, and similar abrupt cooling events followed at 8 mya and 4 mya; by the end of the Tortonian, the Antarctic ice sheet was already much like today in volume and extent. The emergence of most of today's Subantarctic penguin species almost certainly was caused by this sequence of Neogene climate shifts. Penguin ancestry beyond Waimanu remains unknown and not well-resolved by molecular or morphological analyses. The latter tend to be confounded by

15129-606: Was probably the heaviest, weighing 80 kilograms (180 lb) or more. Both were found on New Zealand, the former also in the Antarctic farther eastwards. Traditionally, most extinct species of penguins, giant or small, had been placed in the paraphyletic subfamily called Palaeeudyptinae . More recently, with new taxa being discovered and placed in the phylogeny if possible, it is becoming accepted that there were at least two major extinct lineages. One or two closely related ones occurred in Patagonia , and at least one other—which

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