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The Adélie penguin (''Pygoscelis adeliae'') is a species of
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 ...
common along the entire coast of the
Antarctic The Antarctic (, ; commonly ) is the polar regions of Earth, polar region of Earth that surrounds the South Pole, lying within the Antarctic Circle. It is antipodes, diametrically opposite of the Arctic region around the North Pole. The Antar ...
continent, which is the only place where it is found. It is the most widespread penguin species, and, along with the
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 ...
, is the most southerly distributed of all penguins. It is named after
Adélie Land Adélie Land ( ) or Adélie Coast is a Territorial claims in Antarctica, claimed territory of France located on the continent of Antarctica. It stretches from a portion of the Southern Ocean coastline all the way inland to the South Pole. Franc ...
, in turn, named for Adèle Dumont d'Urville, who was married to French explorer
Jules Dumont d'Urville Jules Sébastien César Dumont d'Urville (; 23 May 1790 – 8 May 1842) was a French List of explorers, explorer and French Navy, naval officer who explored the south and western Pacific, Australia, New Zealand and Antarctica. As a botanist an ...
, who first discovered this penguin in 1840. Adélie penguins obtain their food by both
predation Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...
and
foraging Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavi ...
, with a diet of mainly
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
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 ...
.


Taxonomy and systematics

The first Adélie penguin specimens were collected by crew members of French explorer
Jules Dumont d'Urville Jules Sébastien César Dumont d'Urville (; 23 May 1790 – 8 May 1842) was a French List of explorers, explorer and French Navy, naval officer who explored the south and western Pacific, Australia, New Zealand and Antarctica. As a botanist an ...
on his expedition to Antarctica in the late 1830s and early 1840s. Jacques Bernard Hombron and Honoré Jacquinot, two French surgeons who doubled as naturalists on the journey, described the bird for science in 1841, giving it the
scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...
''Catarrhactes adeliæ''. They used specimens collected from an area of the continent which had been named "terre Adélie", French for
Adélie Land Adélie Land ( ) or Adélie Coast is a Territorial claims in Antarctica, claimed territory of France located on the continent of Antarctica. It stretches from a portion of the Southern Ocean coastline all the way inland to the South Pole. Franc ...
, itself named for Dumont d'Urville's wife, Adèle. The bird was later placed in several other genera, including ''
Eudyptes ''Eudyptes'' is a genus of penguins whose members are collectively called crested penguins. The exact number of species in the genus varies between four and eight depending on the authority, and a Chatham Islands species became extinct in recent ...
'', ''
Pygoscelis The genus ''Pygoscelis'' ("rump-legged") contains three living species of penguins collectively known as "brush-tailed penguins". Taxonomy Mitochondrial and nuclear DNA evidence suggests the genus split from other penguins around 38 milli ...
'' and the now-defunct genus ''Dasyrhamphus'', and was also later inadvertently redescribed as ''Pygoscelis brevirostris''. The Adélie penguin is one of three species now assigned to the
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''
Pygoscelis The genus ''Pygoscelis'' ("rump-legged") contains three living species of penguins collectively known as "brush-tailed penguins". Taxonomy Mitochondrial and nuclear DNA evidence suggests the genus split from other penguins around 38 milli ...
''.
DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
evidence suggests the ''Pygoscelis'' lineage diverged from that of other penguin species some 38 million years ago, roughly 2 million years after the ancestors of the genus '' Aptenodytes'' diverged. Adélie penguins
evolved Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...
about 19 million years ago, branching from the ancestor of the other two members of the genus ( chinstrap and gentoo penguins), both of which evolved some 5 million years later. Although it has no identifiable subspecies, the Adélie penguin has two distinct genetic lineages: one found primarily in 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 ...
, and the other widespread throughout the Antarctic. The genus name ''Pygoscelis'' is a compound word, composed of the
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 ...
words ''pugē'', meaning "rump", and ''skelos'', meaning "leg". The members of this genus are often called "brush-tailed penguins", a reference to their long, stiff tail feathers. The birds regularly use their tails for support, and the stiff feathers sweep the ground as the penguins walk. The specific name ''adeliae'' indicates the location from which the
type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...
was collected.


Description

The Adélie penguin is a mid-sized bird, measuring in length and weighing . Although the sexes look the same, females have shorter wings and beaks and weigh significantly less. The adult is black on the head, throat and upper parts, with snowy white underparts. It has a conspicuous white around a black iris. The
beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for pecking, grasping, and holding (in probing for food, eating, manipulating and ...
is largely covered with black feathers, leaving only the tip exposed; this is primarily black, though it can show indistinct reddish-brown markings. The upper surface of the wing is black with a white trailing edge, while the underside is white with a narrow black leading edge and a small black tip. The legs and feet, which are mostly unfeathered, are pinkish. Upon hatching, the chick is fully covered in down feathers. This coat of feathers is typically silvery-grey (darker on the head), though some birds are much darker overall. Within 10 days, the chick moults into another set of down feathers, this time all dark smoky-grey. Once they have moulted a third time, 7–9 weeks after hatching, the immature birds are similar to adults in appearance, though they tend to be smaller with a bluer tinge to their upperparts and white (rather than black) chins and throats. They lack the full white eye ring of the adult until they are at least a year old.


Similar species

The adult Adélie penguin is unlikely to be confused with any other species, but the white-throated immature bird can resemble the
chinstrap penguin The chinstrap penguin (''Pygoscelis antarcticus'') is a species of penguin that inhabits a variety of islands and shores in the Southern Pacific and the Antarctic Oceans. Its name stems from the narrow black band under its head, which makes it a ...
. However, the black on its face extends below its eyes, and it lacks a black line under the throat (the "chinstrap") that the chinstrap penguin has. In addition, the bill of the chinstrap penguin is longer, and lacks the feathering that covers most of the bill of the Adélie penguin.


Distribution and habitat

The Adélie penguin is a truly Antarctic creature – one of only four penguin species to nest on the continent itself. Breeding colonies are scattered along Antarctica's coasts and on a number of sub-Antarctic islands, including those in the South Orkneys, the South Shetlands, the
South Sandwich Islands The South Sandwich Islands () are a chain of uninhabited volcanic islands in the South Atlantic Ocean. They are administered as part of the British Overseas Territory of South Georgia and the South Sandwich Islands. The chain lies in the sub-A ...
, the Balleny Islands, Scott Island and
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. ...
. The penguins are much less common north of the
60th parallel south The 60th parallel south is a circle of latitude that is 60 degrees south of Earth's equatorial plane. No land lies on the parallel—it crosses nothing but ocean. The closest land is a group of rocks north of Coronation Island (Melson Rocks o ...
but have occurred as vagrants in Australia, New Zealand and southern South America. During the breeding season, they need bare, rocky ground on which to build their nests. They will not nest on ice, and preferentially choose areas where wind or the angle of the sun (or both) helps to keep snow drifts from accumulating. At the start of the breeding seasons, colony sites may be up to from open water, though the distance decreases as summer progresses and the pack ice breaks up. Once they have finished breeding, adult Adélie penguins typically move to ice floes or ice shelves to moult, though some remain onshore. During the winter, the birds remain in the pack ice zone, with most moving north to reach areas where there is visible light for at least part of the day – thus north of roughly 73°S. While some remain near their breeding colonies, others may move hundreds or thousands of kilometres away. As long as there are breaks in the pack ice, they can survive hundreds of kilometres south of open water, and birds are known to forage in winter in areas with up to 80% pack ice cover.


Behaviour and ecology

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 ...
, a survivor of
Robert Falcon Scott Captain Robert Falcon Scott (6 June 1868 – ) was a British Royal Navy officer and explorer who led two expeditions to the Antarctic regions: the Discovery Expedition, ''Discovery'' expedition of 1901–04 and the Terra Nova Expedition ...
's ill-fated British Antarctic Expedition of 1910, documented details of penguin behaviour in his book '' The Worst Journey in the World''. "They are extraordinarily like children, these little people of the Antarctic world, either like children or like old men, full of their own importance..." George Murray Levick, a Royal Navy surgeon-lieutenant and scientist who also accompanied Scott, commented on displays of selfishness among the penguins during his surveying in the Antarctic: "At the place where they most often went in he water a long terrace of ice about six feet in height ran for some hundreds of yards along the edge of the water, and here, just as on the sea-ice, crowds would stand near the brink. When they had succeeded in pushing one of their number over, all would crane their necks over the edge, and when they saw the pioneer safe in the water, the rest followed." Levick also detailed the mating habits of Adélie penguins. One writer observed how the penguin's curiosity could also endanger them, which Scott found a particular nuisance: Others on the mission to the South Pole were more receptive to this element of the Adélies' curiosity. Cherry-Garrard writes: Cherry-Garrard held the birds in great regard. "Whatever a penguin does has individuality, and he lays bare his whole life for all to see. He cannot fly away. And because he is quaint in all that he does, but still more because he is fighting against bigger odds than any other bird, and fighting always with the most gallant pluck, he comes to be considered as something apart from the ordinary bird..." Despite their size, Adélie penguins are known for their bold and boisterous personality and will challenge other animals, including predators far larger than them. In footage shot for the 2018 BBC Earth documentary ''Spy in the Snow'', the boisterous behaviour of Adélie penguins was made especially apparent when an individual arrived to defend a group of emperor penguin chicks that were being menaced by a Southern giant petrel (''Macronectes giganteus''). Despite the species difference between the Adélie and the emperors, the individual charged the petrel, then placed itself between the predator and the chicks until it retreated. Adélie penguins usually swim at around . They are able to leap some out of the water to land on rocks or ice.


Food and feeding

The Adélie penguin is known to feed mainly on
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� ...
, ice krill, Antarctic silverfish,
lanternfish Lanternfish (or myctophids, from the Greek language, Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family (biology), family Myctophidae. One of two families in the order Myctophiformes, ...
(specifically, the Antarctic lanternfish), amphipods ('' Themisto gaudichaudii'', ''Cyllopus lucassi'', '' Hyperia'' and unidentified gammariids), sea
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 ...
, glacial squid and other
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 (diet varies depending on geographic location) during the chick-rearing season. The
stable isotope Stable nuclides are Isotope, isotopes of a chemical element whose Nucleon, nucleons are in a configuration that does not permit them the surplus energy required to produce a radioactive emission. The Atomic nucleus, nuclei of such isotopes are no ...
record of fossil
eggshell An eggshell is the outer covering of a hard-shelled egg (biology), egg and of some forms of eggs with soft outer coats. Worm eggs Nematode eggs present a two layered structure: an external vitellin layer made of chitin that confers mechanical ...
accumulated in colonies over the last 38,000 years reveals a sudden change from a fish-based diet to krill that began around 200 years ago. This is most likely due to the decline of the Antarctic fur seal since the late 18th century and
baleen whale Baleen whales (), also known as whalebone whales, are marine mammals of the order (biology), parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankt ...
s during the early 20th century. The reduction of competition from these predators has resulted in a surplus of krill, which the penguins now exploit as an easier source of food. Jellyfish including species in the genera '' Chrysaora'' and '' Cyanea'' were found to be actively sought-out food items, while they previously had been thought to be only accidentally ingested. Similar preferences were found in the
little penguin The little penguin (''Eudyptula minor'') is the smallest species of penguin. It originates from New Zealand. It is commonly known as the fairy penguin, little blue penguin, or blue penguin, owing to its slate-blue plumage and is also known by ...
,
yellow-eyed penguin The yellow-eyed penguin (''Megadyptes antipodes''), known also as hoiho, is a species of penguin endemic to New Zealand. It is the sole extant species in the genus ''Megadyptes''. Previously thought closely related to the little penguin (''Eud ...
and
Magellanic penguin The Magellanic penguin (''Spheniscus magellanicus'') is a South American penguin, breeding in coastal Patagonia, including Argentina, Chile, and the Falkland Islands, with some bird migration, migrating to Brazil and Uruguay, where they are occas ...
.


Breeding

Adélie penguins breed from October to February on shores around the Antarctic continent. Adélies build rough nests of stones. Two
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 ...
s are laid; these are incubated for 32 to 34 days by the parents taking turns (shifts typically last for 12 days). The chicks remain in the nest for 22 days before joining crèches. The chicks
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 ...
into their juvenile
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 go out to sea after 50 to 60 days. Adélie penguins arrive at their breeding grounds in late October or November, after completing a migration that takes them away from the Antarctic continent for the dark, cold winter months. Their nests consist of stones piled together. In December, the warmest month in Antarctica (about /-19 °C or -2.2 °F), the parents take turns incubating the egg; one goes to feed and the other stays to warm the egg. The parent that is incubating does not eat and does not even leave to defecate but instead projects faeces away from the nest. In March, the adults and their young return to the sea. The Adélie penguin lives on sea ice but needs ice-free land to breed. With a reduction in sea ice, populations of the Adélie penguin have dropped by 65% over the past 25 years in the Antarctic Peninsula. Young Adélie penguins that have no experience in social interaction may react to false cues when the penguins gather to breed. They may, for instance, attempt to mate with other males, with young chicks or with dead females. Levick was the first to record such behaviour (1911–12), but his notes were deemed too indecent for publication at the time; they were rediscovered and published in 2012. "The pamphlet, declined for publication with the official Scott expedition reports, commented on the frequency of sexual activity, auto-erotic behaviour and seemingly aberrant behaviour of young unpaired males and females, including
necrophilia Necrophilia, also known as necrophilism, necrolagnia, necrocoitus, necrochlesis, and thanatophilia, is sexual attraction or acts involving corpses. It is classified as a paraphilia by the World Health Organization (WHO) in its ''International ...
, sexual coercion, sexual and physical abuse of chicks and homosexual behaviour," states the analysis written by Douglas Russell and colleagues William Sladen and David Ainley. "His observations were, however, accurate, valid and, with the benefit of hindsight, deserving of publication." Levick observed the Adélie penguins at Cape Adare, the site of the largest Adélie penguin
rookery A rookery is a colony of breeding rooks, and more broadly a colony of several types of breeding animals, generally gregarious birds. Coming from the nesting habits of rooks, the term is used for corvids and the breeding grounds of colony-fo ...
in the world. , he has been the only one to study this particular colony and he observed it for an entire breeding cycle. The discovery significantly illuminates the behaviour of the species whose population some researchers believe to be a bellwether of
climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
. Some Adélie penguins also actively and deliberately engage in homosexual activity. In one instance recorded in 1996, two wild male individuals courted each other and took turns mounting and copulating with each other. The reciprocal nature of the event indicates that both individuals were aware that they were courting and copulating with another male. The observing researchers suggested that this was practice for heterosexual encounters or a "response to high sexual motivation but a lack of females."


Migration

Adélie penguins living in 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 ...
region in Antarctica migrate an average of about each year as they follow the sun from their breeding colonies to winter foraging grounds and back again. During the winter, the sun does not rise south 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 ...
, but sea ice grows during the winter months and increases for hundreds of miles from the shoreline, and into more northern latitudes, all around Antarctica. As long as the penguins live at the edge of the fast ice, they will see sunlight. As the ice recedes in the spring, the penguins remain on the edge of it, until once again, they are on the shoreline during a sunnier season. The longest treks have been recorded at .


Osmoregulation

Adélie penguins are faced with extreme
osmotic Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region o ...
conditions, as their frozen habitats offer little fresh water. Such desert conditions mean that the vast majority of the available water is highly saline, causing the diets of Adélie penguins to be heavy in salt. They manage to circumvent this problem by eating krill with internal concentrations of salt at the lower end of their possible concentrations, helping to lower the amount of ingested salts. The amount of sodium imposed by this sort of diet is still relatively heavy and can create complications when considering the less tolerant chicks. Adult Adélie penguins feed their chicks by regurgitating the predigested krill, which can impose an excessive salt intake on the chicks. Adult birds address this problem by altering the ion concentrations while the food is still being held in their stomachs. By removing a portion of the sodium and potassium ions, adult Adélie penguins protect their chicks from ingesting excessive amounts of sodium. Adélie penguins also manage their salt intake by concentrating
cloaca A cloaca ( ), : cloacae ( or ), or vent, is the rear orifice that serves as the only opening for the digestive (rectum), reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles, birds, cartilagin ...
l fluids to a much higher degree than most other birds are capable. This ability is present regardless of ontogeny in Adélie penguins, meaning that both adults and juveniles are capable of withstanding extreme levels of salt ion concentration. However, chicks do possess a greater ability to concentrate chloride ions in their cloacal fluids.
Salt gland The salt gland is an organ (anatomy), organ for excreting excess salt (chemistry), salts. It is found in the cartilaginous fishes subclass elasmobranchii (sharks, rays, and skates), seabirds, and some reptiles. Salt glands can be found in the r ...
s also play a major role in the excretion of excess salts. In aquatic birds such as the Adelie penguin, nasal salt glands excrete an extremely concentrated sodium chloride solution, reducing the load on their kidneys. These excretions are crucial in the maintenance of Antarctic ecosystems. Penguin rookeries can be home to thousands of penguins, all of which are concentrating waste products in their digestive tracts and nasal glands. These excretions inevitably drop to the ground. The concentration of salts and nitrogenous wastes helps to facilitate the flow of material from the sea to the land, serving to make it habitable for bacteria which live in the soils.


Threats

Adult Adélie penguins are regularly preyed upon by
leopard seal The leopard seal (''Hydrurga leptonyx''), also referred to as the sea leopard, is the second largest species of seal in the Antarctic (after the southern elephant seal). It is a top order predator, feeding on a wide range of prey including cep ...
s. South polar skuas, in particular, and giant petrels kill many chicks and eat eggs as well. Giant petrels and
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 will occasionally kill adult Adelie penguins.
Kelp gull The kelp gull (''Larus dominicanus''), also known as the Dominican gull, is a gull that breeds on coasts and islands through much of the Southern Hemisphere. The nominate ''L. d. dominicanus'' is the subspecies found around South America, pa ...
s and
snowy sheathbill The snowy sheathbill (''Chionis albus''), also known as the greater sheathbill, pale-faced sheathbill, and paddy, is one of two species of sheathbill. It is usually found on the ground. It is the only land bird native to the Antarctic continent. ...
s also prey on chicks and eggs. In 2024, researchers from
Federation University Australia Federation University Australia (FedUni) is a public university based in Victoria, Australia. It is the modern descendant of the School of Mines Ballarat, established in 1870 as the fourth tertiary institution in Australia, which evolved to f ...
reported more than 532 dead Adélie penguins on Antarctica's Heroína Island, with the
H5N1 Influenza A virus subtype H5N1 (A/H5N1) is a subtype of the influenza A virus, which causes the disease avian influenza (often referred to as "bird flu"). It is enzootic (maintained in the population) in many bird populations, and also panzoo ...
bird flu suspected as the cause. The virus, having arrived in
South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
in 2022, poses a risk to Antarctic wildlife. Samples from the deceased penguins are under analysis, and the H5 strain has been detected in local skua seabirds, potentially facilitating further spread. This situation is particularly concerning for the wildlife of the region, which includes an estimated 20 million pairs of penguins and the already climate-threatened
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 ...
s.


Status

Because of its very large and increasing population (estimated at more than 10 million mature individuals in 2020), and its unfragmented habitat, the Adélie penguin is considered by the
International Union for Conservation of Nature 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 stat ...
to be 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 ...
. A comprehensive census of the global Adélie penguin population was carried out in 2014 using analysis of high-resolution satellite images in combination with actual field surveys. The researchers looked for
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 ...
-discoloured coastal areas (red/brown patches in areas with no snow) in the satellite images, and augmented their findings with field surveys in areas where no good satellite images were available or where the presence of multiple penguins species was suspected. The results of field surveys were only used if they had been done within the previous four years. This census found an estimated 3.79 million breeding pairs in 251 distinct breeding colonies, including more than 40 that had never been surveyed before, a 53% increase over a census completed 20 years earlier. The colonies are distributed around the coastline of the Antarctic land and ocean. Colonies have declined 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. ...
since the early 1980s, but those declines have been more than offset by increases in
East Antarctica East Antarctica, also called Greater Antarctica, constitutes the majority (two-thirds) of the Antarctic continent, lying primarily in the Eastern Hemisphere south of the Indian Ocean, and separated from West Antarctica by the Transantarctic ...
. During the breeding season, they congregate in large breeding colonies, some over a quarter of a million pairs. Individual colonies can vary dramatically in size, and some may be particularly vulnerable to climate fluctuations. The Danger Islands have been identified as an "important bird area" by
BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding i ...
largely because it supports Adélie penguin colonies, with 751,527 pairs recorded in at least five distinct colonies. In March 2018, a colony of 1.5 million was discovered.


See also

* Prostitution among animals


Notes


Citations


References

* * * * * * * * * * * * * * * * *


External links


Adelie penguins at the Polar Conservation Organisation
* {{Authority control
Adélie penguin The Adélie penguin (''Pygoscelis adeliae'') is a species of penguin common along the entire coast of the Antarctic continent, which is the only place where it is found. It is the most widespread penguin species, and, along with the emperor peng ...
Adélie Birds of Antarctica
Adélie penguin The Adélie penguin (''Pygoscelis adeliae'') is a species of penguin common along the entire coast of the Antarctic continent, which is the only place where it is found. It is the most widespread penguin species, and, along with the emperor peng ...
Taxa named by Jacques Bernard Hombron Taxa named by Honoré Jacquinot Articles containing video clips