Penguin

File:Great Auk (Pinguinis impennis) specimen, Kelvingrove, Glasgow - geograph.org.uk - 1108249.jpg

The word penguin first appears in literature at the end of the 16th century as a synonym for the great auk.{{cite book |last1=Fuller |first1=Errol |author1-link=Errol Fuller |title=The Great Auk: The Extinction of the Original Penguin |date=2003 |publisher=Bunker Hill Publishing, Inc. |isbn=978-1-59373-003-1 |page=17 |url=https://books.google.com/books?id=35rGM50pAoAC |language=en}} When European explorers discovered what are today known as penguins in the Southern Hemisphere, they noticed their similar appearance to the great auk of the Northern Hemisphere and named them after this bird, although they are not closely related.

The etymology of the word penguin is still debated. The English word is not apparently of French,{{cite web |url=http://www.cnrtl.fr/etymologie/pingouin |title=PINGOUIN : Etymologie de PINGOUIN |publisher=Centre National de Ressources Textuelles et Lexicales |access-date=January 25, 2010 |archive-url=https://web.archive.org/web/20081026163135/http://www.cnrtl.fr/etymologie/Pingouin |archive-date=October 26, 2008 |url-status=live}} Breton{{OEtymD|penguin}} or Spanish

{{cite encyclopedia |encyclopedia=Diccionario de la lengua española |title=Pingüino |url=http://buscon.rae.es/draeI/SrvltConsulta?TIPO_BUS=3&LEMA=ping%C3%BCino |language=es-ES |edition=22nd |publisher=Real Academia Española |archive-url=https://web.archive.org/web/20110609035102/http://buscon.rae.es/draeI/SrvltConsulta?TIPO_BUS=3&LEMA=ping%C3%BCino |archive-date=June 9, 2011 |url-status=dead |quote=Del fr. pingouin}} origin (the latter two are attributed to the French word {{lang|fr|pingouin}}), but first appears in English or Dutch.

Some dictionaries suggest a derivation from Welsh {{lang|cy|pen}}, 'head' and {{lang|cy|gwyn}}, 'white',{{cite web |url=http://www.etymonline.com/index.php?term=penguin |title=penguin |website=Online Etymology Dictionary |access-date=April 29, 2016 |archive-url=https://web.archive.org/web/20160604130140/http://www.etymonline.com/index.php?term=penguin |archive-date=June 4, 2016 |url-status=live}} including the Oxford English Dictionary, the American Heritage Dictionary,{{cite web |url=http://www.wordnik.com/words/penguin/etymology |title=penguin |work=Wordnik |access-date=October 7, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20110905215701/http://www.wordnik.com/words/penguin |archive-date=September 5, 2011 }} the Century Dictionary and Merriam-Webster,{{cite dictionary |url=http://www.merriam-webster.com/dictionary/penguin |title=Penguin – Definition |dictionary=Merriam-Webster |date=August 31, 2012 |access-date=September 8, 2013 |archive-url=https://web.archive.org/web/20131029185420/http://www.merriam-webster.com/dictionary/penguin |archive-date=October 29, 2013 |url-status=live}} on the basis that the name was originally applied to the great auk, either because it was found on White Head Island ({{langx|cy|Pen Gwyn}}) in Newfoundland, or because it had white circles around its eyes (though the head was black). However, the Welsh word {{lang|cy|pen}} can also be used to mean 'front' and, in a maritime context, {{lang|cy|pen blaen}} means 'front end or part, bow (of a ship), prow'.[https://welsh-dictionary.ac.uk/gpc/gpc.html Geiriadur Prifysgol Cymru]. Retrieved November 22, 2024.

An alternative etymology links the word to Latin {{lang|la|pinguis}}, which means 'fat' or 'oil'.{{cite book |author1=Tui De Roy |author2=Mark Jones |author3=Julie Cornthwaite |title=Penguins:The Ultimate Guide |publisher=Princeton University Press |year=2013 |page=151 }} Support for this etymology can be found in the alternative Germanic word for penguin, {{lang|de|fettgans}} or 'fat-goose', and the related Dutch word {{lang|nl|vetgans}}.

Adult male penguins are sometimes called cocks, females sometimes called hens; a group of penguins on land is a waddle, and a group of penguins in the water is a raft.

{{Main|Great auk}}

Since 1871, the Latin word Pinguinus has been used in scientific classification to name the genus of the great auk (Pinguinus impennis, meaning "plump or fat without flight feathers"),{{cite book|url=https://books.google.com/books?id=tsUzeXV_7jcC&q=egg+%22Great+Auk%22&pg=PA152|title = Who Killed the Great Auk?|first = Jeremy|last = Gaskell|publisher = Oxford University Press (USA)|isbn = 0-19-856478-3|year = 2000|page = 152|access-date = November 18, 2020|archive-date = October 18, 2021|archive-url=https://web.archive.org/web/20211018043926/https://books.google.com/books?id=tsUzeXV_7jcC&q=egg+%22Great+Auk%22&pg=PA152|url-status = live}} which became extinct in the mid-19th century. As confirmed by a 2004 genetic study, the genus Pinguinus belongs in the family of the auks (Alcidae), within the order of the Charadriiformes.{{Cite journal | doi = 10.1186/1471-2148-4-28| year = 2004| title = A supertree approach to shorebird phylogeny| last1 = Thomas | first1 = G. H. | journal = BMC Evolutionary Biology| volume = 4| pages = 28| last2 = Wills | first2 = M. A. | last3 = Székely | first3 = T. S. | pmid=15329156 | pmc=515296| doi-access = free}}{{cite book |last=Johnsgard |first=Paul A. |author-link=Paul Johnsgard |title=Diving Birds of North America |publisher=University of Nebraska Press |location=Lincoln |year=1987 |pages=[https://archive.org/details/divingbirdsofnor0000john/page/265 265–266] |isbn=0-8032-2566-0 |url=https://archive.org/details/divingbirdsofnor0000john/page/265 |access-date=May 11, 2010 |url-access=registration }}

The birds currently known as penguins were discovered later and were so named by sailors because of their physical resemblance to the great auk. Despite this resemblance, however, they are not auks, and are not closely related to the great auk. They do not belong in the genus Pinguinus, and are not classified in the same family and order as the great auk. They were classified in 1831 by Charles Lucien Bonaparte in several distinct genera within the family Spheniscidae and order Sphenisciformes.

{{Main article|List of penguins}}

The family name of Spheniscidae was given by Charles Lucien Bonaparte from the genus Spheniscus,{{cite book |last1=Fraser |first1=Ian |last2=Gray |first2=Jeannie |date=2019 |title=Australian Bird Names: Origins and Meanings |url=https://books.google.com/books?id=aTytDwAAQBAJ&dq=Sphenisciformes&pg=PA86 |location=Clayton South, Victoria, Australia |publisher=CSIRO Publishing |pages=86–87 |isbn=9781486311637 }} the name of that genus comes from the Greek word {{lang|el|σφήν}} sphēn "wedge" used for the shape of an African penguin's swimming flippers.{{cite book |last=Jobling |first=James A. |date=2010 |title=The Helm Dictionary of Scientific Bird Names |location=London, England, UK |publisher=Helm Publishing |page=361 |isbn= 978-1-4081-2501-4 }}

Some recent sources apply the phylogenetic taxon Spheniscidae to what here is referred to as Spheniscinae. Furthermore, they restrict the phylogenetic taxon Sphenisciformes to flightless taxa, and establish the phylogenetic taxon Pansphenisciformes as equivalent to the Linnean taxon Sphenisciformes, i.e., including any flying basal "proto-penguins" to be discovered eventually. Given that neither the relationships of the penguin subfamilies to each other nor the placement of the penguins in the avian phylogeny is presently resolved, this is confusing, so the established Linnean system is followed here.

The number of penguin species is typically listed as between seventeen and nineteen.{{Cite web |last=Hall |first=Danielle |date=April 2018 |editor-last=Fraser |editor-first=Bill |title=Penguins |url=https://ocean.si.edu/ocean-life/seabirds/penguins |access-date=October 27, 2024 |website=Smithsonian Institution}} The International Ornithologists' Union recognizes six genera and eighteen species:{{Cite web |date=August 21, 2024 |title=Kagu, Sunbittern, tropicbirds, loons, penguins |url=https://www.worldbirdnames.org/bow/loons/ |access-date=October 27, 2024 |website=IOC World Bird List}}

File:CSIRO ScienceImage 11266 Penguin tracks.jpg, Tasmania]]

Although the evolutionary and biogeographic history of Sphenisciformes is well-researched, many prehistoric forms are not fully described. Some seminal articles about the evolutionary history of penguins have been published since 2005.{{Cite journal | doi = 10.1111/j.1096-0031.2005.00065.x| title = A phylogeny of extant penguins (Aves: Sphenisciformes) combining morphology and mitochondrial sequences| journal = Cladistics| volume = 21| issue = 3| pages = 209–239| year = 2005| last1 = Bertelli | first1 = S. | last2 = Giannini | first2 = N. P. | s2cid = 85071808}}{{cite journal| doi = 10.1093/molbev/msj124| last1 = Slack| first1 = Kerryn E.| last2 = Jones| first2 = Craig M.| last3 = Ando| first3 = Tatsuro| last4 = Harrison| first4 = G.L. "Abby"| last5 = Fordyce| first5 = R. Ewan| last6 = Arnason| first6 = Ulfur| last7 = Penny| first7 = David| year = 2006| title = Early Penguin Fossils, plus Mitochondrial Genomes, Calibrate Avian Evolution| journal = Molecular Biology and Evolution| volume = 23| issue = #6| pages = 1144–1155| pmid = 16533822| citeseerx = 10.1.1.113.4549}} [http://mbe.oxfordjournals.org/cgi/content/full/msj124/DC1 Supplementary Material] {{Webarchive|url=https://web.archive.org/web/20091216110914/http://mbe.oxfordjournals.org/cgi/content/full/msj124/DC1 |date=December 16, 2009 }}{{overcite|date=October 2024}}

The basal penguins lived around the time of the Cretaceous–Paleogene extinction event in the general area of southern New Zealand and Byrd Land, Antarctica. Due to plate tectonics, these areas were at that time less than {{convert|1500|km|mi}} apart rather than {{convert|4000|km|mi}}. The most recent common ancestor of penguins and Procellariiformes can be roughly dated to the Campanian–Maastrichtian boundary, around 70–68 mya.The exact divergence dates according to Baker et al. (2006) mentioned in this section are not as precisely resolved, due to uncertainties of the molecular clock used.

The oldest known fossil penguin species is Waimanu manneringi, which lived 62 mya in New Zealand. While they were not as well-adapted to aquatic life as modern penguins, Waimanu were flightless, with short wings adapted for deep diving. They swam on the surface using mainly their feet, but the wings were – as opposed to most other diving birds (both living and extinct) – already adapting to underwater locomotion.{{Cite journal | doi = 10.1073/pnas.1304838110| title = High flight costs, but low dive costs, in auks support the biomechanical hypothesis for flightlessness in penguins| journal = Proceedings of the National Academy of Sciences| volume = 110| issue = #23| pages = 9380–9384| year = 2013| last1 = Elliott | first1 = K. H.| last2 = Ricklefs | first2 = R. E.| last3 = Gaston | first3 = A. J.| last4 = Hatch | first4 = S. A.| last5 = Speakman | first5 = J. R.| last6 = Davoren | first6 = G. K. | pmid=23690614 | pmc=3677478| bibcode = 2013PNAS..110.9380E| doi-access = free}}

Perudyptes from northern Peru was dated to 42 mya. An unnamed fossil from Argentina proves that, by the Bartonian (Middle Eocene), some 39–38 mya,Contra Baker et al. (2006). primitive penguins had spread to South America and were in the process of expanding into Atlantic waters.

During the Late Eocene and the Early Oligocene (40–30 mya), some lineages of gigantic penguins existed. Nordenskjoeld's giant penguin was the tallest, growing nearly {{convert|1.80|m|ft|abbr=off|sp=us}} tall. The New Zealand giant penguin was probably the heaviest, weighing {{Convert|80|kg|lb}} or more. Both were found on New Zealand, the former also in the Antarctic farther eastwards.

Traditionally, most extinct species of penguins, giant or small, had been placed in the paraphyletic subfamily called Palaeeudyptinae. More recently, with new taxa being discovered and placed in the phylogeny if possible, it is becoming accepted that there were at least two major extinct lineages. One or two closely related ones occurred in Patagonia, and at least one other—which is or includes the paleeudyptines as recognized today – occurred on most Antarctic and Subantarctic coasts.

Size plasticity was significant at this initial stage of radiation: on Seymour Island, Antarctica, for example, around 10 known species of penguins ranging in size from medium to large apparently coexisted some 35 mya during the Priabonian (Late Eocene). It is not known whether the palaeeudyptines constitute a monophyletic lineage, or whether gigantism was evolved independently in a restricted Palaeeudyptinae and the Anthropornithinae – whether they were considered valid, or whether there was a wide size range present in the Palaeeudyptinae as delimited (i.e., including Anthropornis nordenskjoeldi). The oldest well-described giant penguin, the {{convert|5|ft|m|adj=on}}-tall Icadyptes salasi, existed as far north as northern Peru about 36 mya.

Gigantic penguins had disappeared by the end of the Paleogene, around 25 mya. Their decline and disappearance coincided with the spread of the Squalodontidae and other primitive, fish-eating toothed whales, which competed with them for food and were ultimately more successful. A new lineage, the Paraptenodytes, which includes smaller and stout-legged forms, had already arisen in southernmost South America by that time. The early Neogene saw the emergence of another morphotype in the same area, the similarly sized but more gracile Palaeospheniscinae, as well as the radiation that gave rise to the current biodiversity of penguins.

Modern penguins constitute two undisputed clades and another two more basal genera with more ambiguous relationships. To help resolve the evolution of this order, 19 high-coverage genomes that, together with two previously published genomes, encompass all extant penguin species have been sequenced.{{Cite journal |last1=Pan |first1=Hailin |last2=Cole |first2=Theresa L. |last3=Bi |first3=Xupeng |last4=Fang |first4=Miaoquan |last5=Zhou |first5=Chengran |last6=Yang |first6=Zhengtao |last7=Ksepka |first7=Daniel T. |last8=Hart |first8=Tom |last9=Bouzat |first9=Juan L. |last10=Argilla |first10=Lisa S. |author-link10=Lisa Argilla |last11=Bertelsen |first11=Mads F. |date=September 1, 2019 |title=High-coverage genomes to elucidate the evolution of penguins |url= |journal=GigaScience |language=en |volume=8 |issue=9 |doi=10.1093/gigascience/giz117 |pmc=6904868 |pmid=31531675}} The origin of the Spheniscinae lies probably in the latest Paleogene and, geographically, it must have been much the same as the general area in which the order evolved: the oceans between the Australia-New Zealand region and the Antarctic. Presumably diverging from other penguins around 40 mya, it seems that the Spheniscinae were for quite some time limited to their ancestral area, as the well-researched deposits of the Antarctic Peninsula and Patagonia have not yielded Paleogene fossils of the subfamily. Also, the earliest spheniscine lineages are those with the most southern distribution.

The genus Aptenodytes appears to be the basalmost divergence among living penguins.{{cite journal |doi=10.1111/j.1096-0031.2006.00116.x |last1=Ksepka |first1=D. T. |last2=Bertelli |first2=S. |last3=Giannini |first3=N. P. |title=The phylogeny of the living and fossil Sphenisciformes (penguins) |journal=Cladistics |volume=22 |year=2006 |pages=412–441 |issue=#5 |s2cid=85673628 |doi-access=free }}{{cite book |title=Systematics and Taxonomy of Australian Birds|vauthors=Christidis L, Boles WE |year=2008 |publisher=CSIRO Publishing |location=Canberra |isbn=978-0-643-06511-6 |page=97}} They have bright yellow-orange neck, breast, and bill patches; incubate by placing their eggs on their feet, and when they hatch the chicks are almost naked. This genus has a distribution centred on the Antarctic coasts and barely extends to some Subantarctic islands today.

Pygoscelis contains species with a fairly simple black-and-white head pattern; their distribution is intermediate, centred on Antarctic coasts but extending somewhat northwards from there. In external morphology, these apparently still resemble the common ancestor of the Spheniscinae, as Aptenodytes{{'}} autapomorphies are, in most cases, fairly pronounced adaptations related to that genus' extreme habitat conditions. As the former genus, Pygoscelis seems to have diverged during the Bartonian,

It is likely that, during the Bartonian, there was a near-synchronous but allopatric split between the ancestors of Aptenodytes, Pygoscelis, and the common ancestor of all remaining genera (Baker). but the range expansion and radiation that led to the present-day diversity probably did not occur until much later; around the Burdigalian stage of the Early Miocene, roughly 20–15 mya.

The genera Spheniscus and Eudyptula contain species with a mostly Subantarctic distribution centred on South America; some, however, range quite far northwards. They all lack carotenoid colouration and the former genus has a conspicuous banded head pattern; they are unique among living penguins by nesting in burrows. This group probably radiated eastwards with the Antarctic Circumpolar Current out of the ancestral range of modern penguins throughout the Chattian (Late Oligocene), starting approximately 28 mya. While the two genera separated during this time, the present-day diversity is the result of a Pliocene radiation, taking place some 4–2 mya.

The Megadyptes–Eudyptes clade occurs at similar latitudes (though not as far north as the Galápagos penguin), has its highest diversity in the New Zealand region, and represents a westward dispersal. They are characterized by hairy yellow ornamental head feathers; their bills are at least partly red. These two genera diverged apparently in the Middle Miocene (Langhian, roughly 15–14 mya), although the living species of Eudyptes are the product of a later radiation, stretching from about the late Tortonian (Late Miocene, 8 mya) to the end of the Pliocene.

The geographical and temporal pattern of spheniscine evolution corresponds closely to two episodes of global cooling documented in the paleoclimatic record. The emergence of the Subantarctic lineage at the end of the Bartonian corresponds with the onset of the slow period of cooling that eventually led to the ice ages some 35 million years later. With habitat on the Antarctic coasts declining, by the Priabonian more hospitable conditions for most penguins existed in the Subantarctic regions rather than in Antarctica itself.{{cite journal |author=Baker, A., Pereira, SL, Haddrath, OP, Edge, KA |title=Multiple gene evidence for expansion of extant penguins out of Antarctica due to global cooling |journal=Proceedings of the Royal Society B: Biological Sciences |volume=273 |year=2006 |doi=10.1098/rspb.2005.3260 |issue=#1582 |pages=11–7 |pmid=16519228 |pmc=1560011}} Notably, the cold Antarctic Circumpolar Current also started as a continuous circumpolar flow only around 30 mya, on the one hand forcing the Antarctic cooling, and on the other facilitating the eastward expansion of Spheniscus to South America and eventually beyond. Despite this, there is no fossil evidence to support the idea of crown radiation from the Antarctic continent in the Paleogene, although DNA study favors such a radiation.

Later, an interspersed period of slight warming was ended by the Middle Miocene Climate Transition, a sharp drop in global average temperature from 14 to 12 mya, and similar abrupt cooling events followed at 8 mya and 4 mya; by the end of the Tortonian, the Antarctic ice sheet was already much like today in volume and extent. The emergence of most of today's Subantarctic penguin species almost certainly was caused by this sequence of Neogene climate shifts.

Penguin ancestry beyond Waimanu remains unknown and not well-resolved by molecular or morphological analyses. The latter tend to be confounded by the strong adaptive autapomorphies of the Sphenisciformes; a sometimes perceived fairly close relationship between penguins and grebes is almost certainly an error based on both groups' strong diving adaptations, which are homoplasies. On the other hand, different DNA sequence datasets do not agree in detail with each other either.

File:Spheniscus humboldti -swimming -aquarium-8a.jpg instead of wings.]]

What seems clear is that penguins belong to a clade of Neoaves (living birds except for paleognaths and fowl) that comprises what is sometimes called "higher waterbirds" to distinguish them from the more ancient waterfowl. This group contains such birds as storks, rails, and the seabirds, with the possible exception of the Charadriiformes.{{Cite journal|doi=10.1554/04-235 |url=http://biology-web.nmsu.edu/houde/Parallel_radiations.pdf |pmid=15612298 |title=Parallel Radiations in the Primary Clades of Birds |journal=Evolution |volume=58 |issue=11 |pages=2558–73 |year=2004 |last1=Fain |first1=M. G. |last2=Houde |first2=P. |bibcode=2004Evolu..58.2558F |s2cid=1296408 |url-status=dead |archive-url=https://web.archive.org/web/20130407204436/http://biology-web.nmsu.edu/houde/Parallel_radiations.pdf |archive-date=April 7, 2013 }}

Inside this group, penguin relationships are far less clear. Depending on the analysis and dataset, a close relationship to Ciconiiformes or to Procellariiformes has been suggested. Some think the penguin-like plotopterids (usually considered relatives of cormorants and anhingas) may actually be a sister group of the penguins and those penguins may have ultimately shared a common ancestor with the Pelecaniformes and consequently would have to be included in that order, or that the plotopterids were not as close to other pelecaniforms as generally assumed, which would necessitate splitting the traditional Pelecaniformes into three.{{Cite journal| doi = 10.1111/j.1439-0469.2004.00291.x|url=http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/plotopteridae.pdf| title = Tertiary plotopterids (Aves, Plotopteridae) and a novel hypothesis on the phylogenetic relationships of penguins (Spheniscidae)| journal = Journal of Zoological Systematics and Evolutionary Research| volume = 43| pages = 61–71| year = 2005| last1 = Mayr| first1 = G.| access-date = July 8, 2006| archive-url=https://web.archive.org/web/20061013085236/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/plotopteridae.pdf| archive-date = October 13, 2006| url-status = live}}

A 2014 analysis of whole genomes of 48 representative bird species has concluded that penguins are the sister group of Procellariiformes,{{Cite journal| doi = 10.1126/science.1253451| pmid = 25504713|url=https://pgl.soe.ucsc.edu/jarvis14.pdf| title = Whole-genome analyses resolve early branches in the tree of life of modern birds| journal = Science| volume = 346| issue = #6215| pages = 1320–1331| date = 2014| last1 = Jarvis| first1 = E. D.| author1-link = Erich Jarvis| last2 = Mirarab| first2 = S.| last3 = Aberer| first3 = A. J.| last4 = Li| first4 = B.| last5 = Houde| first5 = P.| last6 = Li| first6 = C.| last7 = Ho| first7 = S. Y. W.| last8 = Faircloth| first8 = B. C.| last9 = Nabholz| first9 = B.| last10 = Howard| first10 = J. T.| last11 = Suh| first11 = A.| last12 = Weber| first12 = C. C.| last13 = Da Fonseca| first13 = R. R.| last14 = Li| first14 = J.| last15 = Zhang| first15 = F.| last16 = Li| first16 = H.| last17 = Zhou| first17 = L.| last18 = Narula| first18 = N.| last19 = Liu| first19 = L.| last20 = Ganapathy| first20 = G.| last21 = Boussau| first21 = B.| last22 = Bayzid| first22 = M. S.| last23 = Zavidovych| first23 = V.| last24 = Subramanian| first24 = S.| last25 = Gabaldon| first25 = T.| last26 = Capella-Gutierrez| first26 = S.| last27 = Huerta-Cepas| first27 = J.| last28 = Rekepalli| first28 = B.| last29 = Munch| first29 = K.| last30 = Schierup| first30 = M.| display-authors = 29| pmc = 4405904| bibcode = 2014Sci...346.1320J| hdl = 10072/67425| access-date = August 28, 2015| archive-url=https://web.archive.org/web/20150224020622/http://pgl.soe.ucsc.edu/jarvis14.pdf| archive-date = February 24, 2015| url-status = dead}} from which they diverged about 60 million years ago (95% CI, 56.8–62.7).{{Cite journal | doi = 10.1186/2047-217X-3-27| title = Two Antarctic penguin genomes reveal insights into their evolutionary history and molecular changes related to the Antarctic environment| journal = GigaScience| volume = 3| issue = #1| pages = 27| date = December 12, 2014| last1 = Li | first1 = C. | last2 = Zhang | first2 = Y. | last3 = Li | first3 = J. | last4 = Kong | first4 = L. | last5 = Hu | first5 = H. | last6 = Pan | first6 = H. | last7 = Xu | first7 = L. | last8 = Deng | first8 = Y. | last9 = Li | first9 = Q. | last10 = Jin | first10 = L. | last11 = Yu | first11 = H. | last12 = Chen | first12 = Y. | last13 = Liu | first13 = B. | last14 = Yang | first14 = L. | last15 = Liu | first15 = S. | last16 = Zhang | first16 = Y. | last17 = Lang | first17 = Y. | last18 = Xia | first18 = J. | last19 = He | first19 = W. | last20 = Shi | first20 = Q. | last21 = Subramanian | first21 = S. | last22 = Millar | first22 = C. D. | last23 = Meader | first23 = S. | last24 = Rands | first24 = C. M. | last25 = Fujita | first25 = M. K. | last26 = Greenwold | first26 = M. J. | last27 = Castoe | first27 = T. A. | last28 = Pollock | first28 = D. D. | last29 = Gu | first29 = W. | last30 = Nam | first30 = K. | display-authors = 29 | pmid=25671092 | pmc=4322438| doi-access = free}}

The distantly related puffins, which live in the North Pacific and North Atlantic, developed similar characteristics to survive in the Arctic and sub-Arctic environments. Like the penguins, puffins have a white chest, black back and short stubby wings providing excellent swimming ability in icy water. But, unlike penguins, puffins can fly, as flightless birds would not survive alongside land-based predators such as polar bears and foxes; there are no such predators in the Antarctic. Their similarities indicate that similar environments, although at great distances, can result in similar evolutionary developments, i.e. convergent evolution.{{Cite book |title=Introduction to Marine Biology |last=Karleskint |first=George |publisher=Cengage Publishing |year=2012 |isbn=978-1285402222 |pages=30 |url=https://books.google.com/books?id=9fEKAAAAQBAJ |access-date=August 15, 2018 |archive-date=July 21, 2020 |archive-url=https://web.archive.org/web/20200721052701/https://books.google.com/books?id=9fEKAAAAQBAJ |url-status=live }}

File:Penguin Wing.svg

File:Taxidermy of a penguin skin.jpg

Penguins are superbly adapted to aquatic life. Their wings have evolved to become flippers, useless for flight in the air. In the water, however, penguins are astonishingly agile. Penguins' swimming looks very similar to birds' flight in the air.{{cite web |url=https://www.youtube.com/watch?v=knZ6E_YV4_c |title=Penguin swimming under water, Galapagos |publisher=Youtube.com |date=April 14, 2008 |access-date=September 8, 2013 |archive-url=https://web.archive.org/web/20140608005622/http://www.youtube.com/watch?v=knZ6E_YV4_c |archive-date=June 8, 2014 |url-status=live }} Within the smooth plumage a layer of air is preserved, ensuring buoyancy. The air layer also helps insulate the birds in cold waters. On land, penguins use their tails and wings to maintain balance for their upright stance.

All penguins are countershaded for camouflage – that is, they have black backs and wings with white fronts.{{cite book|last=Buskey|first=Theresa|title=The Polar Regions|editor=Alan Christopherson, M.S.|publisher=Alpha Omegan Publications, Inc|location=804 N. 2nd Ave. E., Rock Rapids, IA|series=LIFEPAC|chapter=The Antarctic Polar Region|date=March 2001|isbn=978-1-58095-156-2}} A predator looking up from below (such as an orca or a leopard seal) has difficulty distinguishing between a white penguin belly and the reflective water surface. The dark plumage on their backs camouflages them from above.

Gentoo penguins are the fastest underwater birds in the world. They are capable of reaching speeds up to 36 km (about 22 miles) per hour while searching for food or escaping from predators. They are also able to dive to depths of 170–200 meters (about 560–660 feet).{{cite news |last1=Rafferty |first1=John |title=Gentoo Penguin |url=https://www.britannica.com/animal/gentoo-penguin |newspaper=Encyclopedia Britannica |publisher=Encyclopedia Britannica Inc. |access-date=January 20, 2021 |archive-date=January 25, 2021 |archive-url=https://web.archive.org/web/20210125133319/https://www.britannica.com/animal/gentoo-penguin |url-status=live }} The small penguins do not usually dive deep; they catch their prey near the surface in dives that normally last only one or two minutes. Larger penguins can dive deep in case of need. Emperor penguins are the world's deepest-diving birds. They can dive to depths of approximately {{convert|550|m|ft|abbr=off|sp=us}} while searching for food.{{cite web|last1=Rafferty |first1=John |title=Emperor Penguin |url=https://www.britannica.com/animal/emperor-penguin |website=Britannica Online Encyclopedia |publisher=Britannica Encyclopedia Inc. |access-date=January 20, 2021 |archive-date=January 25, 2021 |archive-url=https://web.archive.org/web/20210125140129/https://www.britannica.com/animal/emperor-penguin |url-status=live}}

Penguins either waddle on their feet or slide on their bellies across the snow while using their feet to propel and steer themselves, a movement called "tobogganing", which conserves energy while moving quickly. They also jump with both feet together if they want to move more quickly or cross steep or rocky terrain.

Penguins have an average sense of hearing for birds;{{Cite journal

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}} this is used by parents and chicks to locate one another in crowded colonies.{{Cite journal

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| title = Finding a parent in a king penguin colony: The acoustic system of individual recognition

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}} Their eyes are adapted for underwater vision and are their primary means of locating prey and avoiding predators; in air it has been suggested that they are nearsighted, although research has not supported this hypothesis.{{Cite journal

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File:Pygoscelis papua -Nagasaki Penguin Aquarium -swimming underwater-8a.jpg swimming underwater at the Nagasaki Penguin Aquarium]]

Penguins have a thick layer of insulating feathers that keeps them warm in water (heat loss in water is much greater than in air). The emperor penguin has a maximum feather density of about nine feathers per square centimeter which is actually much lower than other birds that live in Antarctic environments. However, they have been identified as having at least four different types of feather: in addition to the traditional feather, the emperor has afterfeathers, plumules, and filoplumes. The afterfeathers are downy plumes that attach directly to the main feathers and were once believed to account for the bird's ability to conserve heat when under water; the plumules are small down feathers that attach directly to the skin, and are much more dense in penguins than other birds; lastly the filoplumes are small (less than 1 cm long) naked shafts that end in a splay of fibers— filoplumes were believed to give flying birds a sense of where their plumage was and whether or not it needed preening, so their presence in penguins may seem inconsistent, but penguins also preen extensively.{{cite news|title=Busting Myths About Penguin Feathers|author=Ed Young|date=October 20, 2015|url=https://www.nationalgeographic.com/science/phenomena/2015/10/20/busting-myths-about-penguin-feathers/|work=National Geographic|access-date=October 7, 2018|archive-url=https://web.archive.org/web/20181007183640/https://www.nationalgeographic.com/science/phenomena/2015/10/20/busting-myths-about-penguin-feathers/|archive-date=October 7, 2018|url-status=dead}}

The emperor penguin has the largest body mass of all penguins, which further reduces relative surface area and heat loss. They also are able to control blood flow to their extremities, reducing the amount of blood that gets cold, but still keeping the extremities from freezing. In the extreme cold of the Antarctic winter, the females are at sea fishing for food, leaving the males to brave the weather by themselves. They often huddle together to keep warm and rotate positions to make sure that each penguin gets a turn in the centre of the heat pack.

Calculations of the heat loss and retention ability of marine endotherms{{cite journal|last1=Downhower|first1=J.F.|last2=Blumer|first2=L.S.|title=Calculating just how small a whale can be|journal=Nature|date=1988|volume=335|pages=675|doi=10.1038/335675b0|pmid=3173490|issue=#6192|bibcode=1988Natur.335..675D|s2cid=47562824}} suggest that most extant penguins are too small to survive in such cold environments.{{cite book|last1=Williams|first1=T.D.|title=The penguins: Spheniscidae|date=1995|publisher=Oxford University Press|location=New York}} In 2007, Thomas and Fordyce wrote about the "heterothermic loophole" that penguins utilize in order to survive in Antarctica.{{cite journal |last1=Thomas |first1=D.B. |last2=Fordyce |first2=R.E. |author-link2=Ewan Fordyce |date=2007 |title=The heterothermic loophole exploited by penguins |journal=Australian Journal of Zoology |volume=55 |issue=#5 |pages=317–321 |doi=10.1071/zo07053}} All extant penguins, even those that live in warmer climates, have a counter-current heat exchanger called the humeral plexus. The flippers of penguins have at least three branches of the axillary artery, which allows cold blood to be heated by blood that has already been warmed and limits heat loss from the flippers. This system allows penguins to efficiently use their body heat and explains why such small animals can survive in the extreme cold.{{cite journal|last1=Thomas|first1=D.B.|last2=Fordyce|first2=R.E.|title=Biological plasticity in penguin heat-retention structures|journal=Anatomical Record|date=2012|volume=295|issue=#2|pages=249–256|doi=10.1002/ar.21538|pmid=22213564|s2cid=23175291|doi-access=}}

They can drink salt water because their supraorbital gland filters excess salt from the bloodstream.{{cite web |url=http://www.zoo.org/educate/fact_sheets/penguin/penguin.htm |title=Animal Fact Sheets |access-date=July 21, 2006 |url-status=dead |archive-url=https://web.archive.org/web/20060720223700/http://www.zoo.org/educate/fact_sheets/penguin/penguin.htm |archive-date=July 20, 2006 }}{{cite web |url=http://www.stlzoo.org/animals/abouttheanimals/birds/penguins/humboldtpenguin.htm |title=Humboldt Penguin: Saint Louis Zoo |access-date=July 21, 2006 |url-status=dead |archive-url=https://web.archive.org/web/20060928083710/http://www.stlzoo.org/animals/abouttheanimals/birds/penguins/humboldtpenguin.htm |archive-date=September 28, 2006 }}{{cite web|url=http://users.iafrica.com/b/bo/boulders/Vans%20book.htm|author=van der Merwe, H.J.|work=iafrica.com|title=African Penguins and Penguins of the World|access-date=July 21, 2006|archive-url=https://web.archive.org/web/20061012221527/http://users.iafrica.com/b/bo/boulders/Vans%20book.htm|archive-date=October 12, 2006|url-status=dead}} The salt is excreted in a concentrated fluid from the nasal passages.

The great auk of the Northern Hemisphere, now extinct, was superficially similar to penguins, and the word penguin was originally used for that bird centuries ago. They are only distantly related to the penguins, but are an example of convergent evolution.[http://evo.bio.psu.edu/hedgeslab/Publications/PDF-files/128.pdf Convergence and divergence in the evolution of aquatic birds] {{webarchive|url=https://web.archive.org/web/20080529081926/http://evo.bio.psu.edu/hedgeslab/Publications/PDF-files/128.pdf |date=May 29, 2008 }} by Marcel Van Tuinen, Dave Brian Butvill, John A. W. Kirsch and S. Blair Hedges.

File:Penguins on Gourdin Island.jpg Adélie penguin on Gourdin Island]]

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

File:Pygoscelis antarctica trying to get to iceberg.wmv.OGGs in Antarctica]]

{{Css Image Crop|Image = Brown Bluff-2016-Tabarin Peninsula–Gentoo penguin (Pygoscelis papua) 05.jpg|bSize = 450|cWidth = 220|cHeight = 250|oTop = 50|oLeft = 110|Location = right|Description = Gentoo penguin watching over a sleeping chick at Brown Bluff}}

Penguins for the most part breed in large colonies, the exceptions being the yellow-eyed and Fiordland species; these colonies may range in size from as few as 100 pairs for gentoo penguins to several hundred thousand in the case of king, macaroni and chinstrap penguins.Williams, p. 17 Living in colonies results in a high level of social interaction between birds, which has led to a large repertoire of visual as well as vocal displays in all penguin species.Williams, p. 57 Agonistic displays are those intended to confront or drive off, or alternately appease and avoid conflict with, other individuals.

Penguins form monogamous pairs for a breeding season, though the rate the same pair recouples varies drastically. Most penguins lay two eggs in a clutch, although the two largest species, the emperor and the king penguins, lay only one.Williams, p. 23 With the exception of the emperor penguin, where the male does it all, all penguins share the incubation duties.{{Cite journal | doi = 10.1080/03014223.2000.9518236| title = Prolonged foraging trips and egg desertion in little penguins (Eudyptula minor)| journal = New Zealand Journal of Zoology| volume = 27| issue = #4| pages = 277–289| year = 2000| last1 = Numata | first1 = M. | last2 = Davis | first2 = L. S. | last3 = Renner | first3 = M. | doi-access = free}} These incubation shifts can last days and even weeks as one member of the pair feeds at sea.

Penguins generally only lay one brood; the exception is the little penguin, which can raise two or three broods in a season.{{cite book|vauthors=Reilly PN, Balmford P |title=The Biology of Penguins|editor=Stonehouse, Bernard|publisher=Macmillan|location=London|year=1975|pages=161–87|chapter=A breeding study of the little penguin, Eudyptula minor, in Australia |isbn=978-0-333-16791-5}}

Penguin eggs are smaller than any other bird species when compared proportionally to the weight of the parent birds; at {{convert|52|g|oz|0|abbr=on}}, the little penguin egg is 4.7% of its mothers' weight, and the {{convert|450|g|lb|0|abbr=on}} emperor penguin egg is 2.3%. The relatively thick shell forms between 10 and 16% of the weight of a penguin egg, presumably to reduce the effects of dehydration and to minimize the risk of breakage in an adverse nesting environment.{{cite book|author=Meyer-Rochow V.B.|title=Advances in Animal Science and Zoology| editor=Jenkins Owen P.|publisher=Nova Sci Publ Inc|location=Hauppauge, N.Y.|year=2015|pages=65–80|chapter=Examples of four incompletely resolved aspects of the biology of penguins elated to digestive and reproductive physiology, vision and locomotion | isbn =978-1-63483-328-8}} The yolk, too, is large and comprises 22–31% of the egg. Some yolk often remains when a chick is born, and is thought to help sustain the chick if the parents are delayed in returning with food.Williams, p. 24

When emperor penguin mothers lose a chick, they sometimes attempt to "steal" another mother's chick, usually unsuccessfully as other females in the vicinity assist the defending mother in keeping her chick.{{cite news |last1=Gorvett |first1=Zaria |title=If you think penguins are cute and cuddly, you're wrong |url=http://www.bbc.com/earth/story/20151223-if-you-think-penguins-are-cute-and-cuddly-youre-wrong |access-date=March 9, 2020 |work=BBC Earth |date=December 23, 2015 |archive-date=March 8, 2020 |archive-url=https://web.archive.org/web/20200308055345/http://www.bbc.com/earth/story/20151223-if-you-think-penguins-are-cute-and-cuddly-youre-wrong |url-status=live }} In some species, such as emperor and king penguins, the chicks assemble in large groups called crèches.

{{See also|List of Sphenisciformes by population}}

Although almost all penguin species are native to the Southern Hemisphere, they are not found only in cold climates, such as Antarctica. In fact, only a few species of penguin actually live so far south. Several species live in the temperate zone;{{cite web|url=http://www.birdlife.org/worldwide/news/list-penguin-species|access-date=August 8, 2016|title=List of Penguin Species|last=Askew|first=Nick|date=June 24, 2009|publisher=BirdLife International|archive-url=https://web.archive.org/web/20160822014010/http://www.birdlife.org/worldwide/news/list-penguin-species|archive-date=August 22, 2016|url-status=live}}{{Failed verification|date=November 2020}} one, the Galápagos penguin, lives as far north as the Galápagos Islands, but this is only made possible by the cold, rich waters of the Antarctic Humboldt Current that flows around these islands.Piper, Ross (2007), Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press. Also, though the climate of the Arctic and Antarctic regions is similar, there are no penguins found in the Arctic.{{cite book|title = Book: BSCS Biology, By Arnold Brams Grobman.|url=https://books.google.com/books?id=xC-WGtA7eP8C&q=penguins+found+only+pole&pg=PA36|isbn = 9780787290085|last1 = Grobman|first1 = Arnold Brams|year = 1964| publisher=Kendall/Hunt |access-date = November 18, 2020|archive-date = October 18, 2021|archive-url=https://web.archive.org/web/20211018043947/https://books.google.com/books?id=xC-WGtA7eP8C&q=penguins+found+only+pole&pg=PA36|url-status = live}}

File:Gálapagos Penguins Near Isabela Island.jpg

Several authors have suggested that penguins are a good example of Bergmann's Rule{{cite journal |doi=10.1046/j.1466-822X.2002.00313.x |author=Ashton, K. |title=Patterns of within-species body size variation of birds: strong evidence for Bergmann's rule |journal=Global Ecology and Biogeography |volume=11 |year=2002 |pages=505–523 |issue=#6 |bibcode=2002GloEB..11..505A }}{{cite journal |doi=10.1046/j.1365-2699.2003.00837.x |author1=Meiri, S |title=On the validity of Bergmann's rule |journal=Journal of Biogeography |volume=30 |year=2003 |pages=331–351 |issue=#3 |author2=Dayan, T. |bibcode=2003JBiog..30..331M |s2cid=11954818 |url=http://www.tau.ac.il/lifesci/zoology/members/dayan_files/articles/on_the_validity.pdf |access-date=November 13, 2014 |archive-url=https://web.archive.org/web/20150924123741/http://www.tau.ac.il/lifesci/zoology/members/dayan_files/articles/on_the_validity.pdf |archive-date=September 24, 2015 |url-status=live }} where larger-bodied populations live at higher latitudes than smaller-bodied populations. There is some disagreement about this and several other authors have noted that there are fossil penguin species that contradict this hypothesis and that ocean currents and upwellings are likely to have had a greater effect on species diversity than latitude alone.{{cite journal |doi=10.1073/pnas.0611099104 |author=Clarke, J. A.|title=Paleogene equatorial penguins challenge the proposed relationship between biogeography, diversity, and Cenozoic climate change |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=104 |issue=#28 |year=2007 |pages=11545–11550 |pmid=17601778 |pmc=1913862 |last2=Ksepka |last3=Stucchi |last4=Urbina |last5=Giannini |last6=Bertelli |last7=Narváez |last8=Boyd |bibcode=2007PNAS..10411545C |doi-access=free}}{{cite journal |author=Gohlich, U. B. |title=The oldest fossil record of the extant penguin genus Spheniscus – a new species from the Miocene of Peru |url=https://www.app.pan.pl/article/item/app52-285.html |journal=Acta Palaeontologica Polonica |volume=52 |year=2007 |pages=285–298 |access-date=November 13, 2014 |archive-url=https://web.archive.org/web/20141113064147/https://www.app.pan.pl/article/item/app52-285.html |archive-date=November 13, 2014 |url-status=live }}

Major populations of penguins are found in Angola, Antarctica, Argentina, Australia, Chile, Namibia, New Zealand, and South Africa.{{cite web|archive-url=https://web.archive.org/web/20120217205921/http://www.siec.k12.in.us/west/proj/penguins/australia.html|url=http://www.siec.k12.in.us/west/proj/penguins/australia.html|title=Penguins of Australia and New Zealand |publisher=Southern Indian Education Center |access-date=September 8, 2013|archive-date=February 17, 2012 }}{{cite journal |author=Jadwiszczak, P. |title=Penguin past: The current state of knowledge |url=https://www.researchgate.net/publication/230873362 |journal=Polish Polar Research |volume=30 |year=2009 |pages=3–28 |access-date=November 13, 2014 |archive-date=March 7, 2022 |archive-url=https://web.archive.org/web/20220307214202/https://www.researchgate.net/publication/230873362_Penguin_past_The_current_state_of_knowledge |url-status=live }} Satellite images and photos released in 2018 show the population of 2 million in France's remote Ile aux Cochons has collapsed, with barely 200,000 remaining, according to a study published in Antarctic Science.{{Cite web|url=https://www.trtworld.com/life/world-s-biggest-king-penguin-colony-shrinks-90-percent-19260|title=World's biggest king penguin colony shrinks 90 percent|website=World's biggest king penguin colony shrinks 90 percent|language=tr-TR|access-date=August 1, 2018|archive-url=https://web.archive.org/web/20180801124930/https://www.trtworld.com/life/world-s-biggest-king-penguin-colony-shrinks-90-percent-19260|archive-date=August 1, 2018|url-status=live}}

The majority of living penguin species have declining populations. According to the IUCN Red List, their conservation statuses range from Least Concern through to Endangered.

File:CharlesGreenwithPenguin.png on the Endurance preparing an emperor penguin for consumption.]]

Image:AntarcticaSummer.jpg encountering a human during the Antarctic summer]]

Penguins have no special fear of humans and will often approach groups of people. This is probably because penguins have no land predators in Antarctica or the nearby offshore islands. They are preyed upon by other birds like skuas, especially in eggs and as fledglings. Other birds like petrels, sheathbills, and gulls also eat the chicks. Dogs preyed upon penguins while they were allowed in Antarctica during the age of early human exploration as sled dogs, but dogs have long since been banned from Antarctica.{{cite web |title=Removal of the sledge dogs from Antarctica |url=https://www.bas.ac.uk/about/antarctica/environmental-protection/wildlife-and-plants-2/removal-of-the-sledge-dogs/ |archive-url=https://web.archive.org/web/20141113080747/http://www.antarctica.ac.uk/about_antarctica/environment/wildlife/removal_of_sledge_dogs.php |archive-date=November 13, 2014 |publisher=Natural Environment Research Council – British Antarctic Survey |language=en-GB}} Instead, adult penguins are at risk at sea from predators such as sharks, orcas, and leopard seals. Typically, penguins do not approach closer than around {{convert|9|ft|m|abbr=off|sp=us}}, at which point they appear to become nervous.{{Cite web|date=2011|title=beautyofbirds.com|url=https://www.beautyofbirds.com/penguins.html|url-status=bot: unknown|archive-url=https://web.archive.org/web/20210417174014/https://www.beautyofbirds.com/penguins.html|archive-date=April 17, 2021|access-date=April 17, 2021|website=Beauty Of Birds}}

In June 2011, an emperor penguin came ashore on New Zealand's Peka Peka Beach, {{convert|3,200|km|mi}} off course on its journey to Antarctica.{{cite news|url=http://www.3news.co.nz/Emperor-penguin-not-out-of-the-woods-yet/tabid/1160/articleID/216446/Default.aspx| work= 3 News NZ| title= Emperor penguin not out of the woods yet| date= June 25, 2011| access-date= November 21, 2012| archive-url=https://web.archive.org/web/20131210195757/http://www.3news.co.nz/Emperor-penguin-not-out-of-the-woods-yet/tabid/1160/articleID/216446/Default.aspx| archive-date= December 10, 2013| url-status= live}} Nicknamed Happy Feet, after the film of the same name, it was suffering from heat exhaustion and had to undergo a number of operations to remove objects like driftwood and sand from its stomach.{{cite news|url=http://www.3news.co.nz/Happy-Feet-pulls-through-third-operation/tabid/1160/articleID/216660/Default.aspx| work= 3 News NZ| title= Happy Feet pulls through third operation| date= June 27, 2011| access-date= November 21, 2012| archive-url=https://web.archive.org/web/20111214073709/http://www.3news.co.nz/Happy-Feet-pulls-through-third-operation/tabid/1160/articleID/216660/Default.aspx| archive-date= December 14, 2011| url-status= live}} Happy Feet was a media sensation, with extensive coverage on TV and the web, including a live stream that had thousands of views{{cite news|url=http://www.3news.co.nz/The-truth-about-Happy-Feets-home/tabid/367/articleID/221473/Default.aspx| work= 3 News NZ| title= The truth about Happy Feet's home| date= August 8, 2011| access-date= November 21, 2012| archive-url=https://web.archive.org/web/20131210195800/http://www.3news.co.nz/The-truth-about-Happy-Feets-home/tabid/367/articleID/221473/Default.aspx| archive-date= December 10, 2013| url-status= live}} and a visit from English actor Stephen Fry.{{cite news|url=http://www.3news.co.nz/Stephen-Fry-visits-Happy-Feet/tabid/1160/articleID/221822/Default.aspx| work= 3 News NZ| title= Stephen Fry visits Happy Feet| date= August 11, 2011| access-date= November 21, 2012| archive-url=https://web.archive.org/web/20120201121440/http://www.3news.co.nz/Stephen-Fry-visits-Happy-Feet/tabid/1160/articleID/221822/Default.aspx| archive-date= February 1, 2012| url-status= live}} Once he had recovered, Happy Feet was released back into the water south of New Zealand.{{cite news|url=http://www.3news.co.nz/VIDEO-Happy-Feet-starts-the-long-journey-home/tabid/1160/articleID/223894/Default.aspx| work= 3 News NZ| title= Happy Feet starts the long journey home|format=Video| date= August 29, 2011| access-date= November 21, 2012| archive-url=https://web.archive.org/web/20120202111025/http://www.3news.co.nz/VIDEO-Happy-Feet-starts-the-long-journey-home/tabid/1160/articleID/223894/Default.aspx| archive-date= February 2, 2012| url-status= live}}

{{Main|Cultural depictions of penguins}}

Image:Tux.svg, the mascot of the Linux kernel]]

Penguins are widely considered endearing for their unusually upright, waddling gait, swimming ability and (compared to other birds) lack of fear of humans. Their black-and-white plumage is often likened to a white tie suit. Some writers and artists have penguins based at the North Pole, but there are no wild penguins in the Arctic. The cartoon series Chilly Willy helped perpetuate this myth, as the title penguin would interact with Arctic or sub-Arctic species, such as polar bears and walruses.

Penguins have been the subject of many books and films, such as Happy Feet, Surf's Up and Penguins of Madagascar, all CGI films; March of the Penguins, a documentary based on the migration process of the emperor penguin; and Farce of the Penguins, a parody of the documentary. Mr. Popper's Penguins is a children's book written by Richard and Florence Atwater; it was named a Newbery Honor Book in 1939. Penguins have also appeared in a number of cartoons and television dramas, including Pingu, co-created by Otmar Gutmann and Erika Brueggemann in 1990 and covering more than 100 short episodes. At the end of 2009, Entertainment Weekly put it on its end-of-the-decade "best-of" list, saying, "Whether they were walking (March of the Penguins), dancing (Happy Feet), or hanging ten (Surf's Up), these oddly adorable birds took flight at the box office all decade long."Geier, Thom; Jensen, Jeff; Jordan, Tina; Lyons, Margaret; Markovitz, Adam; Nashawaty, Chris; Pastorek, Whitney; Rice, Lynette; Rottenberg, Josh; Schwartz, Missy; Slezak, Michael; Snierson, Dan; Stack, Tim; Stroup, Kate; Tucker, Ken; Vary, Adam B.; Vozick-Levinson, Simon; Ward, Kate, [https://ew.com/article/2009/12/04/100-greatest-movies-tv-shows-and-more/ "The 100 Greatest Movies, TV Shows, Albums, Books, Characters, Scenes, Episodes, Songs, Dresses, Music Videos, and Trends That Entertained Us Over the Past 10 Years"] {{Webarchive|url=https://web.archive.org/web/20140415144141/http://www.ew.com/ew/article/0,,20324138_2,00.html |date=April 15, 2014 }}. Entertainment Weekly. December 11, 2009 (1079/1080):74-84

A video game called Pengo was released by Sega in 1982. Set in Antarctica, the player controls a penguin character who must navigate mazes of ice cubes. The player is rewarded with cut-scenes of animated penguins marching, dancing, saluting and playing peekaboo. Several remakes and enhanced editions have followed, most recently in 2012. Penguins are also sometimes depicted in music.Shuker, R. (2012). Understanding popular music culture. Routledge.{{ISBN|9781317440895}}{{page needed|date=November 2021}}

In 1941, DC Comics introduced the avian-themed character of the Penguin as a supervillain adversary of the superhero Batman (Detective Comics #58). He became one of the most enduring enemies in Batman's rogues gallery. In the 60s Batman TV series, as played by Burgess Meredith, he was one of the most popular characters, and in Tim Burton's reimagining of the story, the character played by Danny Devito in the 1992 film Batman Returns, employed an actual army of penguins (mostly African penguins and king penguins).

Several pro, minor, college and high school sport teams in the United States have named themselves after the species, including the Pittsburgh Penguins team in the National Hockey League and the Youngstown State Penguins in college athletics.

Penguins featured regularly in the cartoons of U.K. cartoonist Steve Bell in his strip in The Guardian newspaper, particularly during and following the Falklands War. Opus the Penguin, from the cartoons of Berkeley Breathed, is also described as hailing from the Falklands. Opus was a comical, "existentialist" penguin character in the cartoons Bloom County, Outland and Opus. He was also the star in the animated Christmas TV special A Wish for Wings That Work.

In the mid-2000s, penguins became one of the most publicized species of animals that form lasting homosexual couples. A children's book, And Tango Makes Three, was written about one such penguin family in the New York Zoo.

{{Reflist|30em|refs=

{{cite journal|ref=Baker|doi=10.1098/rspb.2005.3260|title=Multiple gene evidence for expansion of extant penguins out of Antarctica due to global cooling|journal=Proceedings of the Royal Society B: Biological Sciences|volume=273|issue=#1582|pages=11–7|year=2006|last1=Baker|first1=A. J|last2=Pereira|first2=S. L.|last3=Haddrath|first3=O. P|last4=Edge|first4=K.-A.|pmid=16519228|pmc=1560011}}

{{cite journal |author1=Clarke, Julia A. |author2=Olivero, Eduardo B. |author3=Puerta, Pablo |name-list-style=amp |year=2003 |title=Description of the earliest fossil penguin from South America and first Paleogene vertebrate locality of Tierra Del Fuego, Argentina |journal=American Museum Novitates |issue=3423 |pages=1–18 |url=http://digitallibrary.amnh.org/dspace/bitstream/2246/2788/1/N3423.pdf |doi=10.1206/0003-0082(2003)423<0001:dotefp>2.0.co;2 |hdl=2246/2788 |s2cid=19041678 |access-date=January 4, 2007 |archive-url=https://web.archive.org/web/20070724203258/http://digitallibrary.amnh.org/dspace/bitstream/2246/2788/1/N3423.pdf |archive-date=July 24, 2007 |url-status=live }}

{{cite book| last = Crofford| first = Emily| title = Gone Forever: The Great Auk| place = New York| publisher = Crestwood House| year = 1989| isbn = 978-0-89686-459-7| page = [https://archive.org/details/greatauk0000crof/page/10 10]|url=https://archive.org/details/greatauk0000crof/page/10}}

{{cite journal|author=Jadwiszczak, Piotr|year=2006|title=Eocene penguins of Seymour Island, Antarctica: taxonomy|journal=Polish Polar Research|volume=27|issue=#1|pages=3–62|url=http://www.polish.polar.pan.pl/ppr27/ppr27-003.pdf|access-date=February 2, 2007|archive-url=https://web.archive.org/web/20070724203259/http://www.polish.polar.pan.pl/ppr27/ppr27-003.pdf|archive-date=July 24, 2007|url-status=dead}}

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• {{cite book |ref=Williams |url-access=registration |author1=Williams |author2=Tony D. |year=1995 |url=https://archive.org/details/penguinssphenisc0000will |title=The Penguins – Spheniscidae |place=Oxford |publisher=Oxford University Press |isbn=978-0-19-854667-2}}

{{Sister project links|b=no|commons=Spheniscidae|d=y|n=yes|q=no|s=no|species=Sphenisciformes|v=no}}

{{Library resources box}}

• [https://web.archive.org/web/20070628185533/http://news.nationalgeographic.com/news/2007/06/070625-giant-penguins.html Two new fossil penguin species found in Peru]. news.nationalgeographic.com
• [http://www.pinguins.info/ Information about penguins at pinguins.info]
• [https://web.archive.org/web/20060217020708/http://www.itis.usda.gov/ Integrated Taxonomic Information System] (archived February 17, 2006)
• [https://archive.today/20060315235518/http://www.70south.com/resources/antarctic-animals/antarctic-penguins Penguin information on 70South] (archived March 15, 2006)
• [http://www.penguinpage.net/ Penguin research projects on the web]
• [https://web.archive.org/web/20151227155646/http://ibc.lynxeds.com/family/penguins-spheniscidae Penguin videos and photos] on the Internet Bird Collection (archived December 27, 2015)
• [http://www.penguinworld.com/ Penguin World]
• [https://web.archive.org/web/20080905012627/http://www.teara.govt.nz/EarthSeaAndSky/BirdsOfSeaAndShore/Penguins/en Penguins] in Te Ara: The Encyclopedia of New Zealand the Encyclopedia of New Zealand (archived September 5, 2008)
• [https://web.archive.org/web/20131017221136/http://seaworld.org/animal-info/info-books/penguin/index.htm Seaworld Penguin Information] (archived October 17, 2013)
• [http://www.nwf.org/News-and-Magazines/National-Wildlife/Birds/Archives/2010/Lessons-in-a-Land-of-Wind-and-Ice.aspx "Lessons in a Land of Wind and Ice" from National Wildlife Magazine 1/15/2010]
• [https://curiouspenguins.com Curious Penguins]
• [http://dsc.discovery.com/tv/frozen-planet/penguin-cam/ Live 24/7 camera inside a penguin habitat]

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