The emperor penguin (''Aptenodytes forsteri'') is the tallest and heaviest of all living

penguin Penguins (order Sphenisciformes , family Spheniscidae ) are a group of aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adap ...

species and is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...

. The male and female are similar in

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

and size, reaching in length and weighing from . Feathers of the head and back are black and sharply delineated from the white belly, pale-yellow breast and bright-yellow ear patches. Like all penguins, it is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

. Its diet consists primarily of

fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...

, but also includes

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopoda, isopods, barnacles, copepods, ...

s, such as

krill Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian word ', meaning "small fry of fish", which is also often attributed to species of fish. Krill are consi ...

, and

cephalopod A cephalopod is any member of the molluscan class Cephalopoda ( Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s, such as

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fittin ...

. While hunting, the species can remain submerged around 20 minutes, diving to a depth of . It has several adaptations to facilitate this, including an unusually structured haemoglobin to allow it to function at low oxygen levels, solid bones to reduce

barotrauma Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in tensi ...

, and the ability to reduce its

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run ...

and shut down non-essential organ functions. The only penguin species that breeds during the Antarctic winter, emperor penguins trek over the ice to breeding colonies which can contain up to several thousand individuals. The female lays a single egg, which is incubated for just over two months by the male while the female returns to the sea to feed; parents subsequently take turns foraging at sea and caring for their chick in the colony. The lifespan is typically 20 years in the wild, although observations suggest that some individuals may live to 50 years of age.

Taxonomy

Emperor penguins were described in 1844 by English zoologist

George Robert Gray George Robert Gray FRS (8 July 1808 – 6 May 1872) was an English zoologist and author, and head of the ornithological section of the British Museum, now the Natural History Museum, in London for forty-one years. He was the younger brother ...

, who created the generic name from

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...

word elements, ἀ-πτηνο-δύτης -ptēno-dytēs "without-wings-diver". Its specific name is in honour of the German naturalist

Johann Reinhold Forster Johann Reinhold Forster (22 October 1729 – 9 December 1798) was a German Reformed (Calvinist) pastor and naturalist of partially Scottish descent who made contributions to the early ornithology of Europe and North America. He is best known ...

, who accompanied Captain

James Cook James Cook (7 November 1728 Old Style date: 27 October – 14 February 1779) was a British explorer, navigator, cartographer, and captain in the British Royal Navy, famous for his three voyages between 1768 and 1779 in the Pacific Ocean and ...

on his second voyage and officially named five other penguin species. Forster may have been the first person to see the penguins in 1773–74, when he recorded a sighting of what he believed was the similar

king penguin The king penguin (''Aptenodytes patagonicus'') is the second largest species of penguin, smaller, but somewhat similar in appearance to the emperor penguin. There are two subspecies: ''A. p. patagonicus'' and ''A. p. halli''; ''patagonicus'' ...

(''A. patagonicus'') but given the location, may very well have been ''A. forsteri''. Together with the king penguin, the emperor penguin is one of two extant species in the genus ''

Aptenodytes The genus ''Aptenodytes'' contains two extant species of penguins collectively known as "the great penguins". Etymology The name "Aptenodytes" is a composite of Ancient Greek elements, "ἀ-πτηνο-δύτης" (without-wings-diver). Taxo ...

''.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

evidence of a third species— Ridgen's penguin (''A. ridgeni'')—has been found in fossil records from the late

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58basal; in other words, that it split off from a branch which led to all other living penguin species.

Mitochondria A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used ...

l and

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear ...

DNA evidence suggests this split occurred around 40 million years ago.

Description

Adult emperor penguins are in length, including bill and tail. The weight ranges from and varies by sex, with males weighing more than females. It is the fifth heaviest living bird species, after only the larger varieties of

ratite A ratite () is any of a diverse group of flightless, large, long-necked, and long-legged birds of the infraclass Palaeognathae. Kiwi, the exception, are much smaller and shorter-legged and are the only nocturnal extant ratites. The systematics ...

.''CRC Handbook of Avian Body Masses'' by John B. Dunning Jr. (Editor). CRC Press (1992), . The weight also varies by season, as both male and female penguins lose substantial mass while raising hatchlings and incubating their egg. A male emperor penguin must withstand the extreme Antarctic winter cold for more than two months while protecting his egg. He eats nothing during this time. Most male emperors will lose around while they wait for their eggs to hatch. The mean weight of males at the start of the breeding season is and that of females is . After the breeding season this drops to for both sexes. Like all penguin species, emperor penguins have streamlined bodies to minimize drag while swimming, and wings that are more like stiff, flat flippers. The tongue is equipped with rear-facing barbs to prevent prey from escaping when caught. Males and females are similar in size and colouration. The adult has deep black dorsal feathers, covering the head, chin, throat, back, dorsal part of the flippers, and tail. The black plumage is sharply delineated from the light-coloured plumage elsewhere. The underparts of the wings and belly are white, becoming pale yellow in the upper breast, while the ear patches are bright yellow. The upper mandible of the long bill is black, and the lower mandible can be pink, orange or lilac. In juveniles, the auricular patches, chin and throat are white, while its bill is black. Emperor penguin chicks are typically covered with silver-grey down and have black heads and white masks. A chick with all-white plumage was seen in 2001, but was not considered to be an

albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino. Varied use and interpretation of the term ...

as it did not have pink eyes. Chicks weigh around after hatching, and

fledge Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnera ...

when they reach about 50% of adult weight. The emperor penguin's dark plumage fades to brown from November until February (the Antarctic summer), before the yearly

moult In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...

in January and February. Moulting is rapid in this species compared with other birds, taking only around 34 days. Emperor penguin feathers emerge from the skin after they have grown to a third of their total length, and before old feathers are lost, to help reduce heat loss. New feathers then push out the old ones before finishing their growth.. The average yearly survival rate of an adult emperor penguin has been measured at 95.1%, with an average life expectancy of 19.9 years. The same researchers estimated that 1% of emperor penguins hatched could feasibly reach an age of 50 years. In contrast, only 19% of chicks survive their first year of life.. Therefore, 80% of the emperor penguin population comprises adults five years and older.

Vocalisation

200px, alt=a family of emperor penguins in Antarctica, Emperor penguins and chick vocalizing in Antarctica As the species has no fixed nest sites that individuals can use to locate their own partner or chick, emperor penguins must rely on vocal calls alone for identification.. They use a complex set of calls that are critical to individual recognition between parents, offspring and mates, displaying the widest variation in individual calls of all penguins. Vocalizing emperor penguins use two frequency bands simultaneously. Chicks use a frequency-modulated whistle to beg for food and to contact parents.

Adaptations to cold

The emperor penguin breeds in the coldest environment of any bird species; air temperatures may reach , and wind speeds may reach . Water temperature is a frigid , which is much lower than the emperor penguin's average body temperature of . The species has adapted in several ways to counteract heat loss.. Dense feathers provide 80–90% of its insulation and it has a layer of sub- dermal fat which may be up to thick before breeding.. While the density of contour feathers is approximately 9 per square centimetre (58 per square inch), a combination of dense afterfeathers and

down feather The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator an ...

s (plumules) likely play a critical role for insulation. Muscles allow the feathers to be held erect on land, reducing heat loss by trapping a layer of air next to the skin. Conversely, the plumage is flattened in water, thus waterproofing the skin and the downy underlayer.. Preening is vital in facilitating insulation and in keeping the plumage oily and water-repellent. The emperor penguin is able to

thermoregulate Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

(maintain its core body temperature) without altering its metabolism, over a wide range of temperatures. Known as the thermoneutral range, this extends from . Below this temperature range, its metabolic rate increases significantly, although an individual can maintain its

core temperature Normal human body-temperature (normothermia, euthermia) is the typical temperature range found in humans. The normal human body temperature range is typically stated as . Human body temperature varies. It depends on sex, age, time of day, exer ...

from down to .. Movement by swimming, walking, and shivering are three mechanisms for increasing metabolism; a fourth process involves an increase in the breakdown of fats by enzymes, which is induced by the hormone

glucagon Glucagon is a peptide hormone, produced by alpha cells of the pancreas. It raises concentration of glucose and fatty acids in the bloodstream, and is considered to be the main catabolic hormone of the body. It is also used as a medication to tre ...

.. At temperatures above , an emperor penguin may become agitated as its body temperature and metabolic rate rise to increase heat loss. Raising its wings and exposing the undersides increases the exposure of its body surface to the air by 16%, facilitating further heat loss..

Adaptations to pressure and low oxygen

In addition to the cold, the emperor penguin encounters another stressful condition on deep dives—markedly increased pressure of up to 40 times that of the surface, which in most other terrestrial organisms would cause

. The bones of the penguin are solid rather than air-filled, which eliminates the risk of mechanical barotrauma. While diving, the emperor penguin's oxygen use is markedly reduced, as its heart rate is reduced to as low as 15–20 beats per minute and non-essential organs are shut down, thus facilitating longer dives. Its haemoglobin and

myoglobin Myoglobin (symbol Mb or MB) is an iron- and oxygen-binding protein found in the cardiac and skeletal muscle tissue of vertebrates in general and in almost all mammals. Myoglobin is distantly related to hemoglobin. Compared to hemoglobin, myoglob ...

are able to bind and transport oxygen at low blood concentrations; this allows the bird to function with very low oxygen levels that would otherwise result in loss of consciousness.

Distribution and habitat

Penguin in Antarctica jumping out of the water

The emperor penguin has a circumpolar distribution in the Antarctic almost exclusively between the 66° and 77° south latitudes. It almost always breeds on stable pack ice near the coast and up to offshore. Breeding colonies are usually in areas where ice cliffs and icebergs provide some protection from the wind. Three land colonies have been reported: one (now disappeared) on a shingle spit at the Dion Islands on the

Antarctic Peninsula The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martín in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctic ...

, one on a headland at Taylor Glacier in

Victoria Land Victoria Land is a region in eastern Antarctica which fronts the western side of the Ross Sea and the Ross Ice Shelf, extending southward from about 70°30'S to 78°00'S, and westward from the Ross Sea to the edge of the Antarctic Plateau. I ...

, and most recently one at Amundsen Bay. Since 2009, a number of colonies have been reported on shelf ice rather than

sea ice Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of the Earth's surface and about 12% of the world's o ...

, in some cases moving to the shelf in years when sea ice forms late. The northernmost breeding population is on Snow Island, near the northern tip of the Peninsula. Individual vagrants have been seen on Heard Island,

South Georgia South Georgia ( es, Isla San Pedro) is an island in the South Atlantic Ocean that is part of the British Overseas Territory of South Georgia and the South Sandwich Islands. It lies around east of the Falkland Islands. Stretching in the east� ...

, and occasionally in New Zealand. The total population was estimated in 2009 to be at around 595,000 adult birds, in 46 known colonies spread around the Antarctic and sub-Antarctic; around 35% of the known population lives north of the

Antarctic Circle The Antarctic Circle is the most southerly of the five major circles of latitude that mark maps of Earth. The region south of this circle is known as the Antarctic, and the zone immediately to the north is called the Southern Temperate Zone. So ...

. Major breeding colonies were located at Cape Washington,

Coulman Island Coulman Island is an ice-covered island in the Ross Sea, located southeast of Cape Jones, Victoria Land, Antarctica. It is long, wide and in elevation. Emperor penguins inhabit this island. It was discovered in 1841 by Sir James Clark Ro ...

, Halley Bay, Cape Colbeck, and Dibble Glacier. Colonies are known to fluctuate over time, often breaking into "suburbs" which move apart from the parent group, and some have been known to disappear entirely. The Cape Crozier colony on the Ross Sea shrank drastically between the first visits by the ''Discovery'' Expedition in 1902–03 and the later visits by the ''Terra Nova'' Expedition in 1910–11; it was reduced to a few hundred birds, and may have come close to extinction due to changes in the position of the ice shelf. By the 1960s it had rebounded dramatically, but by 2009 was again reduced to a small population of around 300.

Conservation status

In 2012 the emperor penguin was uplisted from a species of

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. ...

near threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

. Along with nine other species of penguin, it is currently under consideration for inclusion under the US

Endangered Species Act The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...

. The primary causes for an increased risk of species endangerment are declining food availability, due to the

effects of climate change The effects of climate change impact the physical environment, ecosystems and human societies. The environmental effects of climate change are broad and far-reaching. They affect the water cycle, oceans, sea and land ice ( glaciers), sea le ...

and industrial fisheries on the crustacean and fish populations. Other reasons for the species's placement on the Endangered Species Act's list include disease,

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

, and disturbance at breeding colonies by humans. Of particular concern is the impact of tourism. One study concluded that emperor penguin chicks in a crèche become more apprehensive following a helicopter approach to . Population declines of 50% in the Terre Adélie region have been observed due to an increased death rate among adult birds, especially males, during an abnormally prolonged warm period in the late 1970s, which resulted in reduced sea-ice coverage. On the other hand, egg hatching success rates declined when the sea-ice extent increased; chick deaths also increased; The species is therefore considered to be highly sensitive to climatic changes. In 2009, the Dion Islands colony, which had been extensively studied since 1948, was reported to have completely disappeared at some point over the previous decade, the fate of the birds unknown. This was the first confirmed loss of an entire colony. Halley Emperor Penguin Colony in 1999

Beginning in September 2015, a strong El Niño, strong winds, and record low amounts of sea ice resulted in "almost total breeding failure" with the deaths of thousands of emperor chicks for three consecutive years within the Halley Bay colony, the second largest emperor penguin colony in the world. Researchers have attributed this loss to immigration of breeding penguins to the Dawson-Lambton colony south, in which a tenfold population increase was observed between 2016 and 2018. However, this increase is nowhere near the total number of breeding adults formerly at the Halley Bay colony. A

Woods Hole Oceanographic Institution The Woods Hole Oceanographic Institution (WHOI, acronym pronounced ) is a private, nonprofit research and higher education facility dedicated to the study of marine science and engineering. Established in 1930 in Woods Hole, Massachusetts, i ...

study in January 2009 found that emperor penguins could be pushed to the brink of extinction by the year 2100 due to global climate change. The study constructed a mathematical model to predict how the loss of sea ice from climate warming would affect a big colony of emperor penguins at Terre Adélie,

. The study forecasted an 87% decline in the colony's population, from three thousand breeding pairs in 2009 to four hundred breeding pairs in 2100. In June 2014 a study by the

concluded that emperor penguins are at risk from global warming, which is melting the sea ice. This study predicted that by 2100 all 45 colonies of emperor penguins will be declining in numbers, mostly due to loss of habitat. Loss of ice reduces the supply of

, which is a primary food for emperor penguins.

Behaviour

2007 Snow-Hill-Island Luyten-De-Hauwere-Emperor-Penguin-03

] The emperor penguin is a

social animal Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and form cooperative societies. Sociality is a survival response to evolutionary pressures. For example, when a mother wa ...

in its nesting and its foraging behaviour; birds hunting together may coordinate their diving and surfacing. Individuals may be active day or night. A mature adult travels throughout most of the year between the breeding colony and ocean foraging areas; the species disperses into the oceans from January to March. The American

physiologist Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemica ...

Gerry Kooyman revolutionised the study of penguin foraging behaviour in 1971 when he published his results from attaching automatic dive-recording devices to emperor penguins. He found that the species reaches depths of , with dive periods of up to 18 minutes. Later research revealed a small female had dived to a depth of near

McMurdo Sound McMurdo Sound is a sound in Antarctica. It is the southernmost navigable body of water in the world, and is about from the South Pole. Captain James Clark Ross discovered the sound in February 1841, and named it after Lt. Archibald McMurdo ...

. It is possible that emperor penguins can dive for even deeper and longer periods, as the accuracy of the recording devices is diminished at greater depths. Further study of one bird's diving behaviour revealed regular dives to in water around deep, and shallow dives of less than , interspersed with deep dives of more than in depths of . This was suggestive of feeding near or at the sea bottom.. In 1994, a penguin from

Auster rookery Auster Rookery is an Emperor penguin rookery on sea-ice, sheltered by grounded icebergs, east of the Auster Islands, and about ENE of Mawson Station in Antarctica. It was discovered in August 1957 by Flying Officer D. Johnston, RAAF, from an ...

reached a depth of 564 m; the entire dive took him 21.8 min. Both male and female emperor penguins forage for food up to from colonies while collecting food to feed chicks, covering per individual per trip. A male returning to the sea after incubation heads directly out to areas of permanent open water, known as polynyas, around from the colony. An efficient swimmer, the emperor penguin exerts pressure with both its upward and downward strokes while swimming. The upward stroke works against buoyancy and helps maintain depth. Its average swimming speed is . On land, the emperor penguin alternates between walking with a wobbling gait and tobogganing—sliding over the ice on its belly, propelled by its feet and wing-like flippers. Like all penguins, it is flightless. The emperor penguin is a very powerful bird. In one case, a crew of six men, trying to capture a single male penguin for a zoo collection, were repeatedly tossed around and knocked over before all of the men had to collectively tackle the bird, which weighs about half as much as a man. As a defence against the cold, a colony of emperor penguins forms a compact huddle (also known as the turtle formation) ranging in size from ten to several hundred birds, with each bird leaning forward on a neighbour. As the

wind chill Wind chill or windchill (popularly wind chill factor) is the lowering of body temperature due to the passing-flow of lower-temperature air. Wind chill numbers are always lower than the air temperature for values where the formula is valid. When ...

is the least severe in the center of the colony, all the juveniles are usually huddled there. Those on the outside upwind tend to shuffle slowly around the edge of the formation and add themselves to its leeward edge, producing a slow churning action, and giving each bird a turn on the inside and on the outside.

Predators

The emperor penguin's predators include birds and aquatic mammals.

Southern giant petrel The southern giant petrel (''Macronectes giganteus''), also known as the Antarctic giant petrel, giant fulmar, stinker, and stinkpot, is a large seabird of the southern oceans. Its distribution overlaps broadly with the similar northern giant pet ...

s (''Macronectes giganteus'') are the predominant land predator of chicks, responsible for over one-third of chick deaths in some colonies; they also scavenge dead penguins. The south polar skua (''Stercorarius maccormicki'') mainly scavenges for dead chicks, as the live chicks are usually too large to be attacked by the time of its annual arrival in the colony. Occasionally, a parent may attempt to defend its chick from attack, although it may be more passive if the chick is weak or sickly. The only known predators thought to attack healthy adults, and who attack emperor penguins in the water, are both mammals. The first is the leopard seal (''Hydrurga leptonyx''), which takes adult birds and fledglings soon after they enter the water.

Orca The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus '' Orcinus'' and is recognizable by its black-and-white ...

s (''Orcinus orca''), mostly take adult birds, although they will attack penguins of any age in or near water.

Courtship and breeding

Although Emperor penguins can breed at around three years of age, they generally do not begin breeding for another one to three years.. The yearly reproductive cycle begins at the start of the Antarctic winter, in March and April, when all mature emperor penguins travel to colonial nesting areas, often walking inland from the edge of the pack ice.. The start of travel appears to be triggered by decreasing day lengths; emperor penguins in captivity have been induced successfully into breeding by using artificial lighting systems mimicking seasonal Antarctic day lengths. The

British Antarctic Survey The British Antarctic Survey (BAS) is the United Kingdom's national polar research institute. It has a dual purpose, to conduct polar science, enabling better understanding of global issues, and to provide an active presence in the Antarctic on ...

(BAS) used

satellite imagery Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell ima ...

to find new Emperor penguin breeding sites in Antarctica, a discovery that increased the estimated population of the Emperor penguins by 5 to 10 percent to around 278,000 breeding pairs. Given their remote locations and harsh weather conditions, penguin populations are found by scanning aerial imagery and locating enormous pages of ice that have been stained with their

guano Guano (Spanish from qu, wanu) is the accumulated excrement of seabirds or bats. As a manure, guano is a highly effective fertilizer due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. G ...

. The new discoveries increased the number of known breeding sites from 50 to 61. The penguins start

courtship Courtship is the period wherein some couples get to know each other prior to a possible marriage. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marriage. A courtship may be an informal and private m ...

in March or April, when the temperature can be as low as . A lone male gives an ecstatic display, where it stands still and places its head on its chest before inhaling and giving a courtship call for 1–2 seconds; it then moves around the colony and repeats the call. A male and female then stand face to face, with one extending its head and neck up and the other mirroring it; they both hold this posture for several minutes. Once in pairs, couples waddle around the colony together, with the female usually following the male. Before

copulation Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetra ...

, one bird bows deeply to its mate, its bill pointed close to the ground, and its mate then does the same.. Contrary to popular belief, Emperor penguins do not mate for life; they are serially monogamous, having only one mate each year, and remaining faithful to that mate. However, fidelity between years is only around 15%. The narrow window of opportunity available for mating appears to be an influence, as there is a priority to mate and breed which usually precludes waiting for the previous year's partner to arrive at the colony.. The female penguin lays one egg in May or early June; it is vaguely pear-shaped, pale greenish-white, and measures around . It represents just 2.3% of its mother's body weight, making it one of the smallest eggs relative to the maternal weight in any bird species.. 15.7% of the weight of an emperor penguin egg is shell; like those of other penguin species, the shell is relatively thick, which helps minimize risk of breakage. After laying, the mother's food reserves are exhausted and she very carefully transfers the egg to the male, and then immediately returns to the sea for two months to feed. The transfer of the egg can be awkward and difficult, especially for first-time parents, and many couples drop or crack the egg in the process. When this happens, the chick inside is quickly lost, as the egg cannot withstand the sub-freezing temperatures on the icy ground for more than one to two minutes. When a couple loses an egg in this manner, their relationship is ended and both walk back to the sea. They will return to the colony next year to try mating again. After a successful transfer of the egg to the male penguin, the female departs for the sea and the male spends the dark, stormy winter incubating the egg against his

brood patch A brood patch is a patch of featherless skin on the underside of birds during the nesting season. Feathers act as inherent insulators, and prevent efficient incubation. Birds have solved this evolutionary dilemma by developing dedicated brood pat ...

, a patch of skin without feathers. There he balances it on the tops of his feet, engulfing it with loose skin and feathers for around 65-75 consecutive days until hatching. The emperor is the only penguin species where this behaviour is observed; in all other penguin species both parents take shifts incubating. By the time the egg hatches, the male will have fasted for around 120 days since arriving at the colony. To survive the cold and savage winds of up to , the males huddle together, taking turns in the middle of the huddle. They have also been observed with their backs to the wind to conserve body heat. In the four months of travel, courtship, and incubation, the male may lose as much as , from a total mass of . Hatching may take as long as two or three days to complete, as the shell of the egg is thick. Newly hatched chicks are semi-altricial, covered with only a thin layer of down and entirely dependent on their parents for food and warmth. The chick usually hatches before the mother's return, and the father feeds it a

curd Curd is obtained by coagulating milk in a sequential process called curdling. It can be a final dairy product or the first stage in cheesemaking. The coagulation can be caused by adding rennet or any edible acidic substance such as l ...

-like substance composed of 59%

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

and 28%

lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids in ...

, which is produced by a gland in his

oesophagus The esophagus ( American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to ...

. This ability to produce " crop milk" in birds is only found in pigeons, flamingos and male Emperor penguins. The father is able to produce this crop milk to temporarily sustain the chick for generally 4 to 7 days, until the mother returns from fishing at sea with food to properly feed the chick. If the mother penguin is delayed, the chick will die. The young chick is

brooded Egg incubation is the process by which an egg, of oviparous (egg-laying) animals, develops an embryo within the egg, after the egg's formation and ovipositional release. Egg incubation is done under favorable environmental conditions, poss ...

in what is called the ''guard phase'', spending time balanced on its parent's feet and kept warm by the brood patch. The female penguin returns at any time from hatching up to ten days afterwards, from mid-July to early August. She finds her mate among the hundreds of fathers by his vocal call and takes over caring for the chick, feeding it by regurgitating the partially digested fish, squid and krill that she has stored in her stomach. The male is often reluctant to surrender the chick he has been caring for all winter to its mother, but he soon leaves to take his turn at sea, spending 3 to 4 weeks feeding there before returning. The parents then take turns, one

brooding Egg incubation is the process by which an egg, of oviparous (egg-laying) animals, develops an embryo within the egg, after the egg's formation and ovipositional release. Egg incubation is done under favorable environmental conditions, possib ...

while the other forages at sea. If either parent is delayed or fails to return to the colony, the lone parent will return to the sea to feed, leaving the chick to die. Abandoned eggs do not hatch and orphaned chicks never survive. Female emperors who failed to find a mate to breed with, or have lost their own chick may attempt to adopt a stray chick or steal the chick of another female. The mother of the chick and neighboring females will fight to protect the chick or reclaim it, if it has been successfully stolen. These scuffles involving several birds often result in the chick being smothered or trampled to death. Chicks which have been adopted or stolen are quickly abandoned once again, as it is impossible for the female to feed and care for the chick alone. The orphaned chicks wander around the colony attempting to seek food and protection from other adults. They will even try to shelter themselves in an adult bird's brood patch already occupied by their own chick. These stray chicks are brusquely driven away by the adults and their chicks. All orphaned chicks will rapidly become weaker and die of starvation, or freeze to death. About 45–50 days after hatching, the chicks form a crèche, huddling together for warmth and protection. During this time, both parents forage at sea and return periodically to feed their chicks.. A crèche may consist of around a dozen, up to several thousand chicks densely packed together and is essential for surviving the low Antarctic temperatures.. From early November, chicks begin moulting into juvenile plumage, which takes up to two months and is usually not completed by the time they leave the colony. Adults cease feeding them during this time. All birds make the considerably shorter trek to the sea in December and January. The birds spend the rest of the summer feeding there.

Feeding

The emperor penguin's diet consists mainly of fish,

s and

s, although its composition varies from population to population. Fish are usually the most important food source, and the Antarctic silverfish (''Pleuragramma antarcticum'') makes up the bulk of the bird's diet. Other prey commonly recorded include other fish of the family Nototheniidae, the glacial squid (''Psychroteuthis glacialis''), and the

hooked squid The hooked squid, family Onychoteuthidae, currently comprise about 20–25 species (several known from only single life stages and thus unconfirmed), in six or seven genera. They range in mature mantle length from 7 cm to a suggested length ...

species ''

Kondakovia longimana ''Moroteuthopsis longimana'', also known as the giant warty squid or longarm octopus squid,O'Shea, S. 2005''Kondakovia longimana'' In: Giant Squid and Colossal Squid Fact Sheet. The Octopus News Magazine Online. is a large species of hooked squid ...

'', as well as

Antarctic krill Antarctic krill (''Euphausia superba'') is a species of krill found in the Antarctic waters of the Southern Ocean. It is a small, swimming crustacean that lives in large schools, called swarms, sometimes reaching densities of 10,000–30,000 ind ...

(''Euphausia superba''). The emperor penguin searches for prey in the open water of the

Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-smal ...

, in either ice-free areas of open water or tidal cracks in pack ice. One of its feeding strategies is to dive to around , where it can easily spot

sympagic A sympagic environment is one where water exists mostly as a solid, ice, such as a polar ice cap or glacier. Solid sea ice is permeated with channels filled with salty brine. These briny channels and the sea ice itself have its ecology, referred t ...

fish like the

bald notothen The bald notothen (''Pagothenia borchgrevinki''), also known as the bald rockcod, is a species of marine ray-finned fish belonging to the family Nototheniidae, the notothens or cod icefishes. It is native to the Southern Ocean. Taxonomy The bald ...

(''Pagothenia borchgrevinki'') swimming against the bottom surface of the sea-ice; it swims up to the bottom of the ice and catches the fish. It then dives again and repeats the sequence about half a dozen times before surfacing to

breath Breathing (or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen. All aerobic creatures need oxygen for cellu ...

Relationship with humans

In zoos and aquariums

Since the 1930s, there have been several attempts at keeping emperor penguins in captivity. Malcolm Davis of the National Zoological Park made early attempts at keeping penguins, capturing several from Antarctica. He successfully transferred penguins to the National Zoological Park on March 5, 1940, where they lived for up to 6 years. Until the 1960s, keeping attempts were largely unsuccessful, as knowledge of penguin keeping in general was limited and acquired by trial and error. The first to achieve a level of success was

Aalborg Zoo __NOTOC__ Aalborg Zoo is a zoo located near the center of Aalborg in Denmark. Every year, Aalborg Zoo is visited by around 375,000 guests. The zoo covers , and keeps more than 1,500 animals belonging to 126 species. At the entrance, one can se ...

where a chilled house was built especially for this Antarctic species. One individual lived for 20 years at the zoo and a chick was hatched there, but died shortly after. Today, the species is kept at just a few zoos and public aquariums in North America and Asia. Emperor penguins were first successfully bred at SeaWorld San Diego; more than 20 birds have hatched there since 1980. Considered a flagship species, 55 individuals were counted in captivity in North American zoos and aquaria in 1999. In China, the emperor penguin was first bred at Nanjing Underwater World in 2009, followed by Laohutan Ocean Park in

Dalian Dalian () is a major sub-provincial port city in Liaoning province, People's Republic of China, and is Liaoning's second largest city (after the provincial capital Shenyang) and the third-most populous city of Northeast China. Located on ...

in 2010. Since then it has been kept and bred at a few other facilities in China, and the only confirmed twin emperor penguins (the species normally lays just one egg) hatched at Sun Asia Ocean World in Dalian in 2017. In Japan, the species is housed at Port of Nagoya Public Aquarium and Wakayama Adventure World, with successful hatching at Adventure World.

Penguin rescue, rehabilitation and release

In June 2011, a juvenile emperor penguin was found on the beach at

Peka Peka Peka Peka, sometimes spelled Pekapeka, is a seaside locality on the Kapiti Coast of New Zealand's North Island. It is located just off State Highway 1 and the North Island Main Trunk railway between Waikanae and Te Horo. Peka Peka was briefl ...

, north of

Wellington Wellington ( mi, Te Whanganui-a-Tara or ) is the capital city of New Zealand. It is located at the south-western tip of the North Island, between Cook Strait and the Remutaka Range. Wellington is the second-largest city in New Zealand by ...

in New Zealand. He had consumed of sand, which he had apparently mistaken for snow, as well as sticks and stones, and had to undergo a number of operations to remove these to save his life. Following recovery, on 4 September, the juvenile, named "Happy Feet" (after the

2006 film The following is an overview of events in 2006, including the highest-grossing films, award ceremonies and festivals, a list of films released and notable deaths. Evaluation of the year Legendary film critic Philip French of ''The Guardian'' des ...

), was fitted with a tracking device and released into the Southern Ocean north of Campbell Island. However, 8 days later scientists lost contact with the bird, suggesting that the transmitter had fallen off (considered likely) or that he had been eaten by a predator (considered less likely).

Cultural references

The species' unique life cycle in such a harsh environment has been described in print and visual media. Apsley Cherry-Garrard, the Antarctic explorer, wrote in 1922: "Take it all in all, I do not believe anybody on Earth has a worse time than an emperor penguin". Widely distributed in cinemas in 2005, the French documentary ''La Marche de l'empereur'', which was also released with the English title '' March of the Penguins'', told the story of the penguins' reproductive cycle. The subject has been covered for the small screen five times by the BBC and presenter

David Attenborough Sir David Frederick Attenborough (; born 8 May 1926) is an English broadcaster, biologist, natural historian and author. He is best known for writing and presenting, in conjunction with the BBC Natural History Unit, the nine natural histo ...

: first in episode five of the 1993 series on the Antarctic '' Life in the Freezer'', again in the 2001 series ''

The Blue Planet ''The Blue Planet'' is a British nature documentary series created and produced by the BBC. It premiered on 12 September 2001 in the United Kingdom. It is narrated by David Attenborough. Described as "the first ever comprehensive series on t ...

'', once again in the 2006 series '' Planet Earth'', in '' Frozen Planet'' in 2011 and a one-hour programme dedicated to the species in the 2018 series '' Dynasties''. The computer-animated movie '' Happy Feet'' (2006, followed by a sequel '' Happy Feet Two'', 2011) features emperor penguins as its primary characters, with one in particular that loves to dance; although a comedy, it too depicts their life cycle and promotes an underlying serious environmental message of threats from global warming and depletion of food sources by overfishing. The computer-animated movie '' Surf's Up'' (2007) features a surfing emperor penguin named Zeke "Big-Z" Topanga. More than 30 countries have depicted the bird on their stamps – Australia, Great Britain, Chile and France have each issued several. It has also been depicted on a 1962 10 franc stamp as part of an Antarctic expedition series. Canadian band

The Tragically Hip The Tragically Hip, often referred to simply as the Hip, were a Canadian rock band formed in Kingston, Ontario in 1984, consisting of vocalist Gord Downie, guitarist Paul Langlois, guitarist Rob Baker (known as Bobby Baker until 1994), bassi ...

composed the song "Emperor Penguin" for their 1998 album '' Phantom Power''.

DC Comics DC Comics, Inc. ( doing business as DC) is an American comic book publisher and the flagship unit of DC Entertainment, a subsidiary of Warner Bros. Discovery. DC Comics is one of the largest and oldest American comic book companies, with the ...

' crime boss character Oswald Chesterfield Cobblepot, aka "The Penguin", styles himself after an emperor penguin, a fact which is often referenced in stories, e.g., in his occasional alias "Forster Aptenodytes."''Batman'' #257, 1974 - story "Hail Emperor Penguin!" by Dennis O'Neil and

Neal Adams Neal Adams (June 15, 1941 – April 28, 2022) was an American comic book artist. He was the co-founder of the graphic design studio Continuity Associates, and was a Creator ownership, creators-rights advocate who helped secure a pension and re ...

, reprinted in ''The Greatest Batman Stories Ever Told,'' volume 2, 1992.

Tim Burton Timothy Walter Burton (born August 25, 1958) is an American filmmaker and animator. He is known for his gothic fantasy and horror films such as '' Beetlejuice'' (1988), '' Edward Scissorhands'' (1990), '' The Nightmare Before Christmas'' (1993 ...

's film '' Batman Returns'' (1992) reimagines Cobblepot (

Danny DeVito Daniel Michael DeVito Jr. (born November 17, 1944) is an American actor, comedian, and filmmaker. He gained prominence for his portrayal of the taxi dispatcher Louie De Palma in the television series ''Taxi'' (1978–1983), which won him a Gold ...

) as a feral child raised at the Gotham Zoo by emperor penguins, played by little-people actors including Felix Silla. Most other iterations of the character's backstory do not have this element.

Notes

References

External links

University of Michigan info site
with citations for specific studies

Morphology of the emperor penguin
including 3D computed tomographic (CT) animations of skeletons *
Emperor penguin videos, photos & sounds
on the Internet Bird Collection {{Authority control

emperor penguin The emperor penguin (''Aptenodytes forsteri'') is the tallest and heaviest of all living penguin species and is endemic to Antarctica. The male and female are similar in plumage and size, reaching in length and weighing from . Feathers of t ...

Birds of Antarctica

Emperor An emperor (from la, imperator, via fro, empereor) is a monarch, and usually the sovereign ruler of an empire or another type of imperial realm. Empress, the female equivalent, may indicate an emperor's wife ( empress consort), mother ( ...

Articles containing video clips