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

penguin Penguins are a group of aquatic flightless birds from the family Spheniscidae () of the order Sphenisciformes (). They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a sm ...

species and is

endemic Endemism is the state of a species being found only 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 foun ...

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

. The male and female are similar in

plumage Plumage () 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, there can b ...

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 species of penguin, the emperor is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine

habitat In ecology, habitat refers to the array of resources, 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 manifestation of its ...

. Its diet consists primarily of

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

, but also includes

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s, such as

krill Krill ''(Euphausiids)'' (: krill) are small and exclusively marine crustaceans of the order (biology), order Euphausiacea, found in all of the world's oceans. The name "krill" comes from the Norwegian language, Norwegian word ', meaning "small ...

, and

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

s, such as

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

. 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 Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the sole exception of the fish family Channichthyidae. Hemoglobi ...

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 in contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in ...

, and the ability to reduce its

metabolism Metabolism (, from ''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 cellular processes; the co ...

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 of an emperor penguin is typically 20 years in the wild, although observations suggest that some individuals may live as long as 50 years of age.

Taxonomy

Emperor penguins were described in 1844 by English zoologist

George Robert Gray George Robert Gray (8 July 1808 – 6 May 1872) was an English zoology, zoologist and author, and head of the Ornithology, ornithological section of the British Museum, now the Natural History Museum, London, Natural History Museum, London f ...

, who created the generic name from

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

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 pastor and naturalist. Born in Tczew, Dirschau, Pomeranian Voivodeship (1466–1772), Pomeranian Voivodeship, Polish–Lithuanian Commonwealth (now Tczew, Po ...

, who accompanied Captain

James Cook Captain (Royal Navy), Captain James Cook (7 November 1728 – 14 February 1779) was a British Royal Navy officer, explorer, and cartographer famous for his three voyages of exploration to the Pacific and Southern Oceans, conducted between 176 ...

on his second voyage and officially named five other penguin species. Forster may have been the first person to see emperor 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 than but somewhat similar in appearance to the emperor penguin. King penguins mainly eat lanternfish, squid, and krill. On foraging trips, king pen ...

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

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 preserve ...

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

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58basal; in other words, that it split off from a branch which led to all other living penguin species.

Mitochondrial 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 ...

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, averaging according to Stonehouse (1975). Due to the method of

bird measurement Bird measurement or bird biometrics are approaches to quantify the size of birds in scientific studies. The variation in dimensions and weights across birds is one of the fundamental sources of diversity among birds, and even Within species, dimen ...

that measures length between bill to tail, sometimes body length and standing height are confused, and some reported height even reaching tall. There are still more than a few papers mentioning that they reach a standing height of instead of body length. Although standing height of emperor penguin is rarely provided at scientific reports, Prévost (1961) recorded 86 wild individuals and measured maximum height of . Friedman (1945) recorded measurements from 22 wild individuals and resulted height ranging . Ksepka ''et al''. (2012) measured standing height of according to 11 complete skins collected in

American Museum of Natural History The American Museum of Natural History (AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. Located in Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 21 interconn ...

. 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 Ratites () are a polyphyletic group consisting of all birds within the infraclass Palaeognathae that lack keels and cannot fly. They are mostly large, long-necked, and long-legged, the exception being the kiwi, which is also the only nocturnal ...

.''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. Male emperor penguins must withstand the extreme Antarctic winter cold for more than two months while protecting their eggs; eating nothing during this time, male emperors will lose around while waiting 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 Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

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 reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of ...

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 egg, 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 a process by which an animal casts off parts of its body to serve some beneficial purpose, either at ...

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 nesting sites that individuals can use to locate their own partner or chick, emperor penguins must rely on vocal sounds alone for identification.. They use a complex set of calls that are critical to individual recognition between mates, parents and offspring, displaying the widest variation in individual calls of all penguin species. Vocalizing emperor penguins use two

frequency band Spectral bands are regions of a given spectrum, having a specific range of wavelengths or frequencies. Most often, it refers to electromagnetic bands, regions of the electromagnetic spectrum. More generally, spectral bands may also be means in ...

s 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 The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided i ...

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 and p ...

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 (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, exert ...

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 the 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 Glucagon (medic ...

.. 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

and

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

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 Martin 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 Antarctica. ...

, one on a headland at

Taylor Glacier The Taylor Glacier () is a glacier in Antarctica about long, flowing from the plateau of Victoria Land into the western end of Taylor Valley, north of the Kukri Hills. It flows to the south of the Asgard Range. The middle part of the glacier is ...

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 78th parallel south, 78°00'S, and westward from the Ross Sea to the edge of the Ant ...

, and most recently one at

Amundsen Bay Amundsen Bay, also known as Ice Bay, is a long embayment wide, close west of the Tula Mountains in Enderby Land, Antarctica. The bay was seen as a large pack-filled recession in the coastline by Sir Douglas Mawson on 14 January 1930. Seen by Ca ...

. 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 density, dense than water, it floats on the ocean's surface (as does fresh water ice). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world' ...

, in some cases moving to the shelf in years when sea ice forms late. The northernmost breeding population is on

Snow Hill Island Snow Hill Island is an almost completely snowcapped island, long and wide, lying off the east coast of the Antarctic Peninsula. It is separated from James Ross Island to the north-east by Admiralty Sound and from Seymour Island to the north by ...

, near the northern tip of the Peninsula. Individual

vagrants Vagrancy is the condition of wandering homelessness without regular employment or income. Vagrants usually live in poverty and support themselves by travelling while engaging in begging, scavenging, or petty theft. In Western countries, ...

have been seen on Heard Island,

South Georgia South Georgia is an island in the Atlantic Ocean, South Atlantic Ocean that is part of the British Overseas Territories, British Overseas Territory of South Georgia and the South Sandwich Islands. It lies around east of the Falkland Islands. ...

, and occasionally in New Zealand. The furthest north a vagrant has been recorded was in Denmark, Western Australia in November 2024. This individual, which is believed to have originated from eastern Antarctica, was encountered by a group of surfers shortly after it arrived in Denmark, and was taken in by conservationists at the Department of Biodiversity, Conservation and Attractions to have its condition evaluated. In 2009, the total population of emperor penguins was estimated 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 in

, 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 The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who ...

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 downgraded from a species of

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

near threatened A near-threatened species is a species which has been Conservation status, categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to Endangered species, endangerment in the ne ...

by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

. 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; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting and conserving imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...

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

effects of climate change Effects of climate change are well documented and growing for Earth's natural environment and human societies. Changes to the climate system include an Instrumental temperature record, overall warming trend, Effects of climate change on the ...

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 or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

, 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 were 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 EL, El or el may refer to: Arts and entertainment Fictional entities * El, a character from the manga series ''Shugo Chara!'' by Peach-Pit * Eleven (''Stranger Things'') (El), a fictional character in the TV series ''Stranger Things'' * El, fami ...

, 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. Concomitantly, there was 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 was much smaller than the total number of breeding adults lost from the Halley Bay colony. In January 2009, a study from the

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, it i ...

concluded that global climate change could push the emperor penguin to the brink of extinction by the year 2100. 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, Antarctica. 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. Another study by the Woods Hole Oceanographic Institution in 2014 again 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. In December 2022, a new colony at Verleger Point in West Antarctica was discovered by satellite imaging, bringing the total known colonies to 66. In 2023, another study found that more than 90% of emperor penguin colonies could face "quasi-extinction" from "catastrophic breeding failure" due to the loss of sea ice caused by climate change.

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 was ...

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 subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out chemical and ...

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. 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 reached a depth of ; 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

polynya A polynya () is an area of open water surrounded by sea ice. It is now used as a geographical term for an area of unfrozen seawater within otherwise contiguous pack ice or fast ice. It is a loanword from the Russian language, Russian (), whic ...

s, 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 (popularly wind chill factor) is the sensation of cold produced by the wind for a given ambient air temperature on exposed skin as the air motion accelerates the rate of heat transfer from the body to the surrounding atmosphere. Its va ...

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 petrels (''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 known to attack healthy adults, and which attack emperor penguins in the ocean, 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 (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopol ...

s (''Orcinus orca'') mostly take adult birds at sea, 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 list of global issues, global issues, and to provide an active prese ...

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 im ...

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 ) is the accumulated excrement of seabirds or bats. Guano is a highly effective fertiliser due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. Guano was also, to a le ...

. 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 or committed romantic, ''de facto'' relationship. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marri ...

in March or April, when the temperature can be as low as . A lone male gives an ecstatic display, in which 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, 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 An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

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. She carefully transfers the egg to the male and then 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 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 days until hatching. The emperor is the only penguin species where the male alone incubates; 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 , dropping 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 Denaturation (biochemistry), 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, a Kefir cheese, ...

-like substance composed of 59%

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

and 28%

lipid Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing ...

, which is secreted by a gland in his

oesophagus The esophagus (American English), oesophagus (British English), or œsophagus ( archaic spelling) ( see spelling difference) all ; : ((o)e)(œ)sophagi or ((o)e)(œ)sophaguses), colloquially known also as the food pipe, food tube, or gullet, ...

. This ability to produce " crop milk" in birds is only found in pigeons, flamingos and male emperor penguins. After the chick hatches, the father is able to secrete this crop milk for only 3 to 7 days; this will temporarily sustain the chick until the mother returns to the colony with food from fishing at sea to properly feed the chick. If the mother penguin's arrival is delayed, the chick will die. Research indicates that 10–20% of female emperor penguins do not return to their colony from foraging at sea, most victims of the harsh winter weather conditions or predators. The young chick is brooded 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 Broodiness is the action or behavioral tendency to sit on a clutch of eggs to Egg incubation, incubate them, often requiring the non-expression of many other behaviors including feeding and drinking.Homedes Ranquini, J. y Haro-García, F. Zoogen� ...

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 to 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 its 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 from around a dozen to 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 species '' Kondakovia longimana'', as well as

Antarctic krill Antarctic krill (''Euphausia superba'') is a species of krill found in the Antarctica, 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� ...

(''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 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...

, 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 fish like the bald notothen (''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 (spiration or ventilation) is the neuroscience of rhythm, rhythmical process of moving air into (inhalation) and out of (exhalation) the lungs to facilitate gas exchange with the Milieu intérieur, internal environment, mostly to flu ...

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 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, considered a

flagship species In conservation biology, a flagship species is a species chosen to raise support for biodiversity conservation in a given place or social context. Definitions have varied, but they have tended to focus on the strategic goals and the socio-economi ...

, 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 SeaWorld San Diego is a theme park in Mission Bay Park in San Diego, California. It is a marine mammal park, oceanarium, public aquarium, and marine animal rehabilitation center. SeaWorld, the theme park's proprietor, is owned and operated by Un ...

; more than 20 birds have hatched there since 1980. Fifty-five 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 (after Shenyang ...

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 the

Port of Nagoya Public Aquarium The is a public aquarium in Minato-ku, Nagoya, Aichi Prefecture, Japan. It is a member of the Japanese Association of Zoos and Aquariums (JAZA), and It is the public aquarium with the largest tank capacity and total area in Japan. It also own ...

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, north of

Wellington Wellington 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 third-largest city in New Zealand (second largest in the North Island ...

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), 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 Apsley George Benet Cherry-Garrard (2 January 1886 – 18 May 1959) was an English explorer of Antarctica. He was a member of the Terra Nova Expedition, ''Terra Nova'' expedition and is acclaimed for his 1922 account of this expedition, ''T ...

, 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 ''March of the Penguins'' ( French ''La Marche de l'empereur''; ) is a 2005 French feature-length nature documentary directed and co-written by Luc Jacquet, and co-produced by Bonne Pioche and the National Geographic Society. The documentary d ...

'', told the story of the penguins' reproductive cycle. The subject has been covered for the small screen five times by the

BBC The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in London, England. Originally established in 1922 as the British Broadcasting Company, it evolved into its current sta ...

and presenter

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

: first in episode five of the 1993 series on the Antarctic '' Life in the Freezer'', again in the 2001 series '' The Blue Planet'', once again in the 2006 series ''

Planet Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is ...

'', in '' Frozen Planet'' in 2011 and a one-hour programme dedicated to the species in the 2018 series ''

Dynasties A dynasty is a sequence of rulers from the same family, usually in the context of a monarchical system, but sometimes also appearing in republics. A dynasty may also be referred to as a "house", "family" or "clan", among others. Historians ...

''. The 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 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 The franc is any of various units of currency. One franc is typically divided into 100 centimes. The name is said to derive from the Latin inscription ''francorum rex'' (King of the Franks) used on early French coins and until the 18th century ...

stamp as part of an Antarctic expedition series. Canadian band

The Tragically Hip The Tragically Hip, often referred to simply as the Hip, was 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), bassis ...

composed the song "Emperor Penguin" for their 1998 album ''

Phantom Power Phantom power, in the context of Professional audio, professional audio equipment, is Direct current, DC electric power equally applied to both signal wires in Balanced line, balanced microphone cables, forming a phantom circuit, to power m ...

''. '' The Emperor Lays an Egg'' is a 2004 non-fiction children's picture book by Brenda Z. Guiberson.

DC Comics DC Comics (originally DC Comics, Inc., and also known simply as DC) is an American comic book publisher owned by DC Entertainment, a subsidiary of Warner Bros. Discovery. DC is an initialism for "Detective Comics", an American comic book seri ...

' 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.

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 The word ''emperor'' (from , via ) can mean the male ruler of an empire. ''Empress'', the female equivalent, may indicate an emperor's wife (empress consort), mother/grandmother (empress dowager/grand empress dowager), or a woman who rules ...

Emperor penguin The emperor penguin (''Aptenodytes forsteri'') is the tallest and heaviest of all living penguin species and is Endemism in birds, endemic to Antarctica. The male and female are similar in plumage and size, reaching in length and weighing fr ...

Birds of Antarctica

emperor penguin The emperor penguin (''Aptenodytes forsteri'') is the tallest and heaviest of all living penguin species and is Endemism in birds, endemic to Antarctica. The male and female are similar in plumage and size, reaching in length and weighing fr ...

Articles containing video clips