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{{short description|Family of aquatic flightless birds}}
{{Other uses}}
{{pp-semi-indef}}
{{Use mdy dates|date=November 2014}}
{{Automatic taxobox
| name = Penguins
| fossil_range = ]-recent, {{fossilrange|62|0}}
| image = South Shetland-2016-Deception Island–Chinstrap penguin (Pygoscelis antarctica) 04.jpg
| image_caption = ] <br />(''Pygoscelis antarctica'')
| parent_authority = ], 1891
| taxon = Spheniscidae
| authority = ], 1831
| range_map = Penguin range.png
| range_map_caption = Range of penguins, all species (aqua)
| subdivision_ranks = Modern ]
| subdivision =
'']''<br />
'']''<br />
'']''<br />
'']''<br />
'']''<br />
'']''<br />
For prehistoric genera, see ]
}}

'''Penguins''' (] '''Sphenisciformes''', ] '''Spheniscidae''') are a group of ] birds. They live almost exclusively in the ], with only one species, the ], found north of the equator. Highly adapted for life in the water, penguins have ] dark and white ] and flippers for swimming. Most penguins feed on ], ], ] and other forms of ] which they catch while swimming underwater. They spend roughly half of their lives on land and the other half in the sea.

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 live so far south. Several species are found in the ] zone, but one species, the ], lives near the equator.

The largest living species is the ] (''Aptenodytes forsteri''):<ref>{{Cite book|url=https://books.google.com/?id=TQjLDAAAQBAJ&pg=PA124&dq=largest+living+species+of+penguin+is+the+emperor+penguin#v=onepage&q=largest%20living%20species%20of%20penguin%20is%20the%20emperor%20penguin&f=false|title=Animal!|last=DK|date=2016-09-06|publisher=Penguin|isbn=9781465459008|language=en}}</ref> on average, adults are about {{convert|1.1|m|ftin|abbr=on}} tall and weigh {{convert|35|kg|lb|abbr=on}}. The smallest penguin species is the ] (''Eudyptula minor''), also known as the fairy penguin, which stands around {{convert|33|cm|in|abbr=on}} tall and weighs {{convert|1|kg|lb|abbr=on}}.<ref name="pengsent">{{cite web|url=http://mesh.biology.washington.edu/penguinProject/Little|title=Little Penguin - Penguin Project|last=Grabski|first=Valerie|year=2009|publisher=Penguin Sentinels/University of Washington|url-status=dead|archiveurl=https://web.archive.org/web/20111216162812/http://mesh.biology.washington.edu/penguinProject/Little|archivedate=16 December 2011|accessdate=25 November 2011}}</ref> Among extant penguins, larger penguins inhabit colder regions, while smaller penguins are generally found in temperate or even tropical climates. Some ] species attained enormous sizes, becoming as tall or as heavy as an adult human. These were not restricted to Antarctic regions; on the contrary, ] regions harboured high diversity, and at least one giant penguin occurred in a region around 2,000&nbsp;km south of the ] 35&nbsp;]<!-- the distance is accurate for 35 million years ago; it is closer to the equator today -->, in a climate decidedly warmer than today.{{which|date=October 2018}}

==Etymology==
]s (''Aptenodytes forsteri'') in Antarctica.]]
The word ''penguin'' first appears in the 16th century as a synonym for ].<ref name="CNRTL" >{{cite web |url=http://www.cnrtl.fr/etymologie/pingouin |title=PINGOUIN : Etymologie de PINGOUIN |publisher=Centre National de Ressources Textuelles et Lexicales |accessdate=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}}</ref> When European explorers discovered what are today known as penguins in the Southern Hemisphere, they noticed their ] to the great auk of the ], and named them after this bird, although they are not closely related.<ref name="Crofford10"/>

The etymology of the word ''penguin'' is still debated. The English word is not apparently of ],<ref name="CNRTL"/> ]<ref name="Online Etymology Dictionary">{{OEtymD|penguin}}</ref> or ]<ref name="DRAE"> {{Webarchive|url=https://web.archive.org/web/20160411193652/http://buscon.rae.es/draeI/SrvltConsulta?TIPO_BUS=3&LEMA=ping%C3%BCino |date=April 11, 2016 }}. Diccionario de la lengua española. rae.es</ref> origin (the latter two are attributed to the French word {{lang|fr|pingouin}} "]"), but first appears in English or Dutch.<ref name="CNRTL"/>

Some dictionaries suggest a derivation from ] {{lang|cy|pen}}, "head" and {{lang|cy|gwyn}}, "white",<ref>{{cite web |url=http://www.etymonline.com/index.php?term=penguin |title=penguin |accessdate=29 April 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}}</ref> including the '']'', the '']'',<ref name="AHD">{{cite web |url=http://www.wordnik.com/words/penguin/etymology |title=penguin |work=Wordnik.com |accessdate=October 7, 2014 |url-status=dead |archiveurl=https://web.archive.org/web/20141016075523/https://www.wordnik.com/words/penguin/etymology |archivedate=October 16, 2014}}</ref> the '']''<ref name="AHD"/> and '']'',<ref name="MW">{{cite dictionary |url=http://www.merriam-webster.com/dictionary/penguin |title=Penguin – Definition |dictionary=] |date=August 31, 2012 |accessdate=September 8, 2013 |archiveurl=https://web.archive.org/web/20131029185420/http://www.merriam-webster.com/dictionary/penguin |archivedate=October 29, 2013 |url-status=live}}</ref> on the basis that the name was originally applied to the ], either because it was found on ] ({{lang-cy|Pen Gwyn}}) in Newfoundland, or because it had white circles around its eyes (though the head was black).

An alternative etymology links the word to ] {{lang|la|pinguis}}, which means "fat" or "oil".<ref>{{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 }}</ref> 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 called ''cocks'', females ''hens''; a group of penguins on land is a ''waddle'', and a similar group in the water is a ''raft''.

=== Pinguinus ===
{{Main|Great auk}}
Since 1871, the Latin word ''Pinguinus'' has been used in ] to name the genus of the ] (''Pinguinus impennis'', meaning "penguin without ]s"),<ref name="Gaskell">{{cite book|url =https://books.google.com/?id=tsUzeXV_7jcC&pg=PA152&lpg=PA152&dq=egg+%22Great+Auk%22 |title = Who Killed the Great Auk?| first = Jeremy |last =Gaskell |publisher = Oxford University Press (USA)|isbn = 0-19-856478-3 |year = 2000|page= 152}}</ref> which became ] in the mid-19th century. As confirmed by a 2004 genetic study, the genus ''Pinguinus'' belongs in the family of the ]s (Alcidae), within the order of the ].<ref>{{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}}</ref><ref name="Johnsgard">{{cite book |last=Johnsgard |first=Paul A. |title=Diving Birds of North America |publisher=University of Nebraska Press |location=Lincoln |year=1987 |pages= |isbn=0-8032-2566-0 |url=https://archive.org/details/divingbirdsofnor0000john/page/265 |accessdate=11 May 2010 |url-access=registration }}</ref>

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 they are not closely related to the great auk.<ref name="Crofford10"/><ref name="Gaskell" /> They do not belong in the genus ''Pinguinus'', and are not classified in the same family and order as the great auks. They were classified in 1831 by ] in several distinct genera within the family ] and order ].

==Systematics and evolution==

===Living species and recent extinctions===
] (''Pygoscelis adeliae'') feeding young. Like its relatives, a neatly bi-coloured species with a head marking.]]
]s (''Spheniscus magellanicus''). The closed neck collar denotes this species.]]
] (''Eudyptes chrysocome'') displaying its distinctive crest]]
]s and one ] on a beach on ], British overseas territory]]
The number of extant penguin ] is debated. Depending on which authority is followed, penguin ] varies between 17 and 20 living species, all in the ] Spheniscinae. Some sources consider the ] a separate '']'' species, while others treat it as a subspecies of the ];<ref name="Williams">]</ref><ref name="Davis & Renner"/> the actual situation seems to be more complicated.<ref name="Banks"/> Similarly, it is still unclear whether the ] is merely a colour morph of the ]. The status of the ]s is also unclear.

Updated after Marples (1962),<ref name="Marples"/> Acosta Hospitaleche (2004),<ref name="Acosta"/> and Ksepka ''et al.'' (2006).<ref name="Ksepka"/>

'''Subfamily Spheniscinae''' – modern penguins
{| class="wikitable"
|-
! Image !! Genus !! Living Species
|-
|]||''''']''''' {{small|Miller,JF, 1778}} – great penguins||
* ], ''Aptenodytes patagonicus''
* ], ''Aptenodytes forsteri''
|-
|]||''''']''''' {{small|Wagler, 1832}} – brush-tailed penguins||
* ], ''Pygoscelis adeliae''
* ], ''Pygoscelis antarctica''
* ], ''Pygoscelis papua''
|-
|]||''''']''''' {{small|Bonaparte, 1856}} – little penguins||
* ], ''Eudyptula minor''
* ], ''Eudyptula novaehollandiae''
* ], ''Eudyptula albosignata'' (provisional)
|-
|]||''''']''''' {{small|Brisson 1760}} – banded penguins||
* ], ''Spheniscus magellanicus''
* ], ''Spheniscus humboldti''
* ], ''Spheniscus mendiculus''
* ], ''Spheniscus demersus''
|-
|]||''''']''''' {{small|Milne-Edwards, 1880}}||
* ], ''Megadyptes antipodes''
* †], ''Megadyptes waitaha'' (extinct)
|-
|]||''''']''''' {{small|Vieillot, 1816}} – crested penguins||
* ], ''Eudyptes pachyrynchus''
* ], ''Eudyptes robustus''
* ], ''Eudyptes sclateri''
* ], ''Eudyptes chrysocome''
* ], ''Eudyptes filholi''
* ], ''Eudyptes moseleyi''
* ], ''Eudyptes schlegeli'' (disputed)
* ], ''Eudyptes chrysolophus''
* †], ''Eudyptes chathamensis'' (extinct)
|-
|}

===Fossil genera===
{{cladogram|title=Phylogeny of Spheniscidae<ref>{{cite journal| journal=] |volume=8 | issue=1927 |pages=1927 |doi=10.1038/s41467-017-01959-6 |pmid=29233963 |pmc=5727159 |last=Mayr |first=Gerald |last2=Scofield |first2=R. Paul |last3=Vanesa L. |first3=De Pietri |last4=Tennyson |first4=Alan J. D. |year=2017 |title=''A Paleocene penguin from New Zealand substantiates multiple origins of gigantism in fossil Sphenisciformes'' |bibcode=2017NatCo...8.1927M }}</ref>
|{{clade|style=font-size:90%;line-height:80%;width:250px
|1={{Clade
|1=†'']''
|2={{Clade
|1=†'']''
|2={{Clade
|1=†'']''
|2={{Clade
|1={{Clade
|1=†'']''
|2=†'']''
}}
|2={{Clade
|1=†'']''
|2={{Clade
|1=†'']''
|2={{Clade
|1=†'']''
|2={{Clade
|1={{Clade
|1=†'']''
|2=†'']''
}}
|2={{Clade
|1=†'']''
|2={{Clade
|1=†'']''
|2={{Clade
|1=†'']''
|2=]
}}
}}
}}
}}
}}
}}
}}
}}
}}
}}
}}
}}
|}}

'''Order Sphenisciformes'''<ref>{{cite web |website=Mikko's Phylogeny Archive |last=Haaramo |first=Mikko |year= |title=''Sphenisciformes – penguins'' |url=http://www.helsinki.fi/~mhaaramo/metazoa/deuterostoma/chordata/archosauria/aves/procellariimorphae/sphenisciformes.html |accessdate=30 December 2017 |archive-url=https://web.archive.org/web/20181203155243/http://www.helsinki.fi/~mhaaramo/metazoa/deuterostoma/chordata/archosauria/aves/procellariimorphae/sphenisciformes.html |archive-date=December 3, 2018 |url-status=live }}</ref>
* '''] and unresolved taxa''' (all ])
** '']'' (Middle Miocene)
** '']'' (San Julian Late Eocene/Early Oligocene – Patagonia Early Miocene of Patagonia, Argentina)<!-- American Museum novitates 2488:1. Cladistics22:412 where lapsus "-dyptes". --><!-- AmMusNovit2488:1. -->
** '']'' <small>Hospitaleche, Reguero & Santillana 2017</small>
** '']'' (Cross Valley Late Paleocene of Seymour Island, Antarctica)
** '']'' <small>Wiman 1905</small>
** '']'' (Late Early-Middle Paleocene of Takatika Grit, New Zealand)
** '']'' <small>Fordyce & Tomas 2011</small> (Maxwell's penguin)
** '']'' (Late Oligocene of S Canterbury, New Zealand)
** '']'' (Late Pliocene)
** '']'' (Late Paleocene of Canterbury, New Zealand)
** '']'' (Early Pliocene of Duinfontain, South Africa)<!-- Cladistics22:412. - lapsus "Nucleaornis" -->
** '']'' <small>Wiman 1905</small>
** '']'' (Late Oligocene/Early Miocene of Argentina)
** '']'' (Late Miocene/Early Pliocene)
** '']'' (Late Paleocene)
** '']'' <small>Van Tets & O’Connor 1983 nomen dubium</small> (Hunter Island penguins)
** '']'' (Middle Pliocene of New Zealand)
** '']'' (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)
** '']'' (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)
* '''Spheniscidae''']'']]
** '']'' <small>Jones, Ando & Fordyce 2006</small> (Middle-Late Paleocene)
** '']'' <small>Mayr, 2017</small>
** '']'' <small>Wiman 1905</small> (Middle/Late Eocene? – Early Oligocene of Seymour Island, Antarctica)<!-- Cladistics22:412. -->
** '']'' <small>Myrcha et al. 2002</small> (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)<!-- Cladistics22:412. -->
** '']'' <small>Myrcha et al. 2002</small> (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)<!-- Cladistics22:412. -->
** '']'' <small>Clarke et al. 2007</small> (Middle Eocene of Atacama Desert, Peru)
** '']'' <small>Wiman 1905</small> (Middle Eocene? – Early Oligocene of Seymour Island, Antarctica)<!-- Cladistics22:412 -->
** '']'' <small>Huxley 1859</small> (Middle/Late Eocene – Late Oligocene)
** '']'' <small>Clarke et al. 2007</small> (Late Eocene of Atacama Desert, Peru)
** '']'' <small>Oliver 1930</small> (Late Eocene)
** '']'' <small>Clarke et al. 2010</small> (Late Eocene of South America)
** '']'' <small>Ksepka et al. 2012</small> (Late Oligocene of E South Island, New Zealand)
** '']'' <small>Ameghino 1891</small> (Early – Late Miocene/Early Pliocene)
** '']'' <small>Marples 1952</small> (Middle/Late Eocene – Late Oligocene)
** '']'' <small>Marples 1953</small> (Late Oligocene of Otago, New Zealand)
** '']'' <small>Marples 1952</small> (Late Oligocene of New Zealand)<ref>{{cite web | title = Platydyptes novaezealandiae; holotype | work = Collections Online | publisher = Museum of New Zealand Te Papa Tongarewa | url = http://collections.tepapa.govt.nz/objectdetails.aspx?oid=314359 | accessdate = July 16, 2010 | archive-url = https://web.archive.org/web/20110824114837/http://collections.tepapa.govt.nz/objectdetails.aspx?oid=314359 | archive-date = August 24, 2011 | url-status = live }}</ref>
** '']'' <small>Simpson 1979</small> (Early Pliocene of South Africa) – possibly Spheniscinae<!-- Cladistics22:412. -->
** '']'' <small>Simpson 1972</small> (Early Pliocene) <!-- Cladistics22:412. -->
** '''Subfamily ]''' (slender-footed penguins) (])
*** '']'' <small>Olson 1986</small> (Patagonia Early Miocene of Patagonia, Argentina)<!-- Cladistics22:412. -->
*** '']'' <small>Moreno & Mercerat 1891</small> (Early? – Late Miocene/Early Pliocene) – includes ''Chubutodyptes''
** '''Subfamily ]
*** Spheniscidae gen. et sp. indet. CADIC P 21 (Leticia Middle Eocene of Punta Torcida, Argentina)<ref name="Clarke"/>
*** Spheniscidae gen. et sp. indet. (Late Oligocene/Early Miocene of Hakataramea, New Zealand)<ref name="Baker"/>
*** '']'' (Puerto Madryn Late Miocene of Argentina)<!-- *ActaPalaeontolPol52:299. -->

The ] genus '']'' was formerly thought to belong to Spheniscidae, however reexamination of the holotype in 1943 resulted in the genus being placed in ].<ref name="Simpson1946">{{cite journal |last= Simpson, G.G. |year= 1946 |title= Fossil penguins |journal= Bulletin of the American Museum of Natural History |volume= 81 |url= http://digitallibrary.amnh.org/dspace/bitstream/2246/392/1/B087a01.pdf |access-date= September 25, 2010 |archive-url= https://web.archive.org/web/20070811030524/http://digitallibrary.amnh.org/dspace/bitstream/2246/392/1/B087a01.pdf |archive-date= August 11, 2007 |url-status= live }}</ref> Further examination in 1980 resulted in placement as Aves ''incertae sedis''.<ref name="olson1985">{{cite journal |doi=10.2307/2408747 |pmid=28561505 |last1=Olson |first1=S.L. |year=1985 |title=Faunal Turnover in South American Fossil Avifaunas: The Insufficiencies of the Fossil Record |journal=Evolution |volume=39 |issue=5 |pages=1174–1177 |url=http://si-pddr.si.edu/dspace/bitstream/10088/6499/1/VZ_169_S_Amer_fossil_avifaunas.pdf |jstor=2408747 |access-date=September 25, 2010 |archive-url=https://web.archive.org/web/20090717162821/http://si-pddr.si.edu/dspace/bitstream/10088/6499/1/VZ_169_S_Amer_fossil_avifaunas.pdf |archive-date=July 17, 2009 |url-status=live }}</ref>

===Taxonomy===
Some recent sources<ref name="Ksepka"/><ref name="Clarke"/> apply the ] 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 ] Sphenisciformes,<ref name="Clarke"/> 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 ] is presently resolved, this is confusing, so the established Linnean system is followed here.

===Evolution===
], ]]]
The ]ary history of penguins is well-researched and represents a showcase of evolutionary ]. Although penguin bones of any one species vary much in size and few good specimens are known, the ] of many prehistoric forms still leaves much to be desired. Some seminal articles about penguin prehistory have been published since 2005;<ref name="Ksepka"/><ref name="Baker"/><ref name="B&G">{{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. }}</ref><ref name="Slack">{{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 = ]| volume = 23| issue = 6| pages = 1144–1155| pmid = 16533822| pmc = | url = http://mbe.oxfordjournals.org/cgi/reprint/23/6/1144| ref = harv| citeseerx = 10.1.1.113.4549| access-date = February 4, 2007| archive-url = https://web.archive.org/web/20070311042244/http://mbe.oxfordjournals.org/cgi/reprint/23/6/1144| archive-date = March 11, 2007| url-status = live}} {{Webarchive|url=https://web.archive.org/web/20091216110914/http://mbe.oxfordjournals.org/cgi/content/full/msj124/DC1 |date=December 16, 2009 }}</ref> the evolution of the living genera can be considered resolved by now.

The ] penguins lived around the time of the ] somewhere in the general area of (southern) New Zealand and ], Antarctica.<ref name="Ksepka"/> Due to ], these areas were at that time less than {{convert|1500|km|mi}} apart rather than the {{convert|4000|km|mi}} of today. The ] of penguins and their ] can be roughly dated to the ]–] boundary, around 70–68 mya.<ref name="Baker"/><ref name="Slack"/><ref>The exact divergence dates according to ] ''et al.'' (2006) mentioned in this section are not as precisely resolved as it appears to be due to uncertainties of the ] used.</ref>
What can be said as certainly as possible in the absence of direct (i.e., fossil) evidence is that, by the end of the ], the penguin lineage must have been evolutionarily well distinct, though much less so ]; it is fairly likely that they were not yet entirely flightless at that time, as flightless birds have generally low resilience to the breakdown of ]s that follows the initial phase of mass extinctions because of their below-average dispersal capabilities (''see also'' ]).{{Citation needed|date=February 2010}}

====Basal fossils====
The oldest known ] penguin species is ''Waimanu manneringi'', which lived in the early ] epoch of New Zealand, or about 62 ].<ref name="Slack"/> While they were not as well-adapted to aquatic life as modern penguins, '']'' were generally ]-like birds but already flightless, with short wings adapted for deep diving.<ref name="Slack"/> 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.<ref>{{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}}</ref>

''Perudyptes'' from northern Peru was dated to 42 mya. An unnamed fossil from ] proves that, by the ] (Middle ]), some 39–38 mya,<ref>''Contra'' ] ''et al.'' (2006).</ref> primitive penguins had spread to ] and were in the process of expanding into ] waters.<ref name="Clarke"/>

====Palaeeudyptines====
During the Late Eocene and the Early ] (40–30 mya), some lineages of gigantic penguins existed. ] was the tallest, growing nearly {{convert|1.80|m|ft|abbr=off|sp=us}} tall. The ] was probably the heaviest, weighing 80&nbsp;kg 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 ] ] called ]. More recently, with new taxa being discovered and placed in the ] if possible, it is becoming accepted that there were at least two major extinct lineages. One or two closely related ones occurred in ], and at least one other—which is or includes the paleeudyptines as recognized today – occurred on most ] and ] coasts.

But size plasticity seems to have been great at this initial stage of penguin ]: on ], Antarctica, for example, around 10 known species of penguins ranging in size from medium to huge apparently coexisted some 35 mya during the ] (Late Eocene).<ref name="Jadwiszczak"/> It is not even known whether the gigantic palaeeudyptines constitute a ] lineage, or whether gigantism was evolved independently in a much restricted Palaeeudyptinae and the Anthropornithinae – whether they were considered valid, or whether there was a wide size range present in the Palaeeudyptinae as delimited as usually done these days (i.e., including '']'').<ref name="Ksepka"/> The oldest well-described giant penguin, the {{convert|5|ft|m|adj=on}}-tall '']'', actually occurred as far north as northern ] about 36 mya.

In any case, the gigantic penguins had disappeared by the end of the ], around 25 mya. Their decline and disappearance coincided with the spread of the Squalodontoidea and other primitive, fish-eating ]s, which certainly competed with them for food, and were ultimately more successful.<ref name="Baker"/> A new lineage, the ], which includes smaller but decidedly stout-legged forms, had already arisen in southernmost South America by that time. The early ] saw the emergence of yet another morphotype in the same area, the similarly sized but more gracile ], as well as the radiation that gave rise to the penguin ] of our time.

====Origin and systematics of modern penguins====
Modern penguins constitute two undisputed ]s and another two more basal genera with more ambiguous relationships.<ref name="B&G"/> To help resolve the evolution of this ], 19 high-coverage genomes that, together with 2 previously published genomes, encompass all extant penguin species have been sequenced.<ref>{{Cite journal|last=Pan|first=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.|last11=Bertelsen|first11=Mads F.|date=2019-09-01|title=High-coverage genomes to elucidate the evolution of penguins|url=https://academic.oup.com/gigascience/article/8/9/giz117/5571031|journal=GigaScience|language=en|volume=8|issue=9|doi=10.1093/gigascience/giz117|pmid=31531675|pmc=6904868}}</ref> 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.<ref name="Baker"/> Presumably diverging from other penguins around 40 mya,<ref name="Baker"/> it seems that the Spheniscinae were for quite some time limited to their ancestral area, as the well-researched deposits of the ] and ] have not yielded Paleogene fossils of the subfamily. Also, the earliest spheniscine lineages are those with the most southern distribution.

The genus '']'' appears to be the basalmost divergence among living penguins<ref name="Ksepka">{{cite journal |doi=10.1111/j.1096-0031.2006.00116.x |author=Ksepka, D. T. B., Sara; Giannini, Norberto P |lastauthoramp=yes |title=The phylogeny of the living and fossil Sphenisciformes (penguins) |journal=Cladistics |volume=22 |year=2006 |pages=412–441 |issue=5 }}</ref><ref name=CB08>{{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}}</ref> 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.

'']'' 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 ], these apparently still resemble the common ancestor of the Spheniscinae, as ''Aptenodytes''{{'}} ]ies are in most cases fairly pronounced ] related to that genus' extreme ] conditions. As the former genus, ''Pygoscelis'' seems to have diverged during the Bartonian,<ref>
It is likely that, during the Bartonian, there was a near-synchronous but ] split between the ancestors of ''Aptenodytes'', ''Pygoscelis'', and the common ancestor of all remaining genera (]).</ref> but the range expansion and radiation that led to the present-day diversity probably did not occur until much later; around the ] stage of the Early ], roughly 20–15 mya.<ref name="Baker"/>

The ] '']'' and '']'' contain species with a mostly Subantarctic distribution centred on ]; some, however, range quite far northwards. They all lack ] 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 ] out of the ancestral range of modern penguins throughout the ] (Late Oligocene), starting approximately 28 mya.<ref name="Baker"/> While the two genera separated during this time, the present-day diversity is the result of a ] radiation, taking place some 4–2 mya.<ref name="Baker"/>

The ''Megadyptes''–''Eudyptes'' clade occurs at similar ]s (though not as far north as the ]), 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 (], roughly 15–14 mya), but again, the living species of ''Eudyptes'' are the product of a later radiation, stretching from about the late ] (Late Miocene, 8 mya) to the end of the Pliocene.<ref name="Baker"/>

====Geography====
The geographical and temporal pattern or spheniscine evolution corresponds closely to two episodes of ] documented in the ].<ref name="Baker" /> 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 ] 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.<ref name="Baker, A., Pereira, SL, Haddrath, OP, Edge, KA 2006">{{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}}</ref> 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 '']'' to South America and eventually beyond.<ref name="Baker" /> 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.<ref name="Baker, A., Pereira, SL, Haddrath, OP, Edge, KA 2006"/>

Later, an interspersed period of slight warming was ended by the ], a sharp drop in global average temperature from 14–12 mya, and similar abrupt cooling events followed at 8 mya and 4 mya; by the end of the Tortonian, the ] 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.

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

] instead of wings.]]
What seems clear is that penguins belong to a clade of ] (living birds except ]s and ]) that comprises what is sometimes called "]" to distinguish them from the more ancient ]. This group contains such birds as ]s, ], and the ]s, with the possible exception of the ].<ref>{{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. |url-status=dead |archiveurl=https://web.archive.org/web/20130407204436/http://biology-web.nmsu.edu/houde/Parallel_radiations.pdf |archivedate=April 7, 2013 }}</ref>

Inside this group, penguin relationships are far less clear. Depending on the analysis and dataset, a close relationship to ]<ref name="Slack"/> or to ]<ref name="Baker"/> has been suggested. Some think the penguin-like ] (usually considered relatives of ]s and ]s) may actually be a sister group of the penguins and those penguins may have ultimately shared a common ancestor with the ] 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 in three.<ref>{{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}}</ref><!-- presumed this ref covers the entire statement -->

A 2014 analysis of whole genomes of 48 representative bird species has concluded that penguins are the ] of Procellariiformes,<ref name = "Jarvis2014">{{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| 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}}</ref> from which they diverged about 60 million years ago (95% CI, 56.8-62.7).<ref name = "LiC2014">{{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 = 2014-12-12| 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}}</ref>

The distantly related ]s, 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. ].<ref>{{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}}</ref>

==Anatomy and physiology==
]
]
Penguins are superbly adapted to ] life. Their ]s 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 bird's flight in the air.<ref>{{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 |accessdate=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 }}</ref> Within the smooth ] a layer of air is preserved, ensuring buoyancy. The air layer also helps insulate the birds in cold waters. On land, penguins use their ]s and wings to maintain balance for their upright stance.

All penguins are ] for ] – that is, they have black backs and ]s with white fronts.<ref>{{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|isbn=978-1-58095-156-2}}</ref> A predator looking up from below (such as an ] or a ]) has difficulty distinguishing between a white penguin belly and the reflective water surface. The dark plumage on their backs camouflages them from above.

Diving penguins reach {{convert|6|to|12|km/h|mph|abbr=on}}, though there are reports of velocities of {{convert|27|km/h|mph|abbr=on}} (which are more realistic in the case of startled flight).{{citation needed|date=December 2010}} 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. Dives of the large emperor penguin have been recorded reaching a depth of {{convert|565|m|ft|abbr=on}} for up to 22 minutes.{{cn|date=February 2020}}

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 ] for birds;<ref name="Wever">{{Cite journal
| pmid = 5259756|jstor=59401
| pmc = 223504
| year = 1969
| last1 = Wever
| first1 = E. G.
| title = Hearing in the blackfooted penguin, ''Spheniscus demersus'', as represented by the cochlear potentials
| journal = Proceedings of the National Academy of Sciences of the United States of America
| volume = 63
| issue = 3
| pages = 676–80
| last2 = Herman
| first2 = P. N.
| last3 = Simmons
| first3 = J. A.
| last4 = Hertzler
| first4 = D. R.
| doi=10.1073/pnas.63.3.676
| bibcode = 1969PNAS...63..676W
}}</ref> this is used by parents and chicks to locate one another in crowded ].<ref name="Jouventin">{{Cite journal
| pmid = 10373249
| year = 1999
| last1 = Jouventin
| first1 = P
| title = Finding a parent in a king penguin colony: The acoustic system of individual recognition
| journal = Animal Behaviour
| volume = 57
| issue = 6
| pages = 1175–1183
| last2 = Aubin
| first2 = T
| last3 = Lengagne
| first3 = T
| doi = 10.1006/anbe.1999.1086
| url = https://semanticscholar.org/paper/5d4d70e104b656ac8b1cb68e3e9b7b1d7ea781d5
}}</ref> 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 ], although research has not supported this hypothesis.<ref name="Sivak">{{Cite journal
| pmid = 2881308|jstor=36191
| year = 1987
| last1 = Sivak
| first1 = J
| title = Vision of the Humboldt penguin (''Spheniscus humboldti'') in air and water
| journal = Proceedings of the Royal Society of London B
| volume = 229
| issue = 1257
| pages = 467–72
| last2 = Howland
| first2 = H. C.
| last3 = McGill-Harelstad
| first3 = P
| doi=10.1098/rspb.1987.0005
| bibcode = 1987RSPSB.229..467S
}}</ref>
] swimming underwater at 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 ] 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 ]s, ]s, and ]s. 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&nbsp;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.<ref>{{cite news|title=Busting Myths About Penguin Feathers|author=Ed Young|date=20 October 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=live}}</ref>

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 <ref name="Calculating">{{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}}</ref> suggest that most extant penguins are too small to survive in such cold environments.<ref name="The penguins">{{cite book|last1=Williams|first1=T.D.|title=The penguins: Spheniscidae|date=1995|publisher=Oxford University Press|location=New York}}</ref> In 2007, Thomas and Fordyce wrote about the "heterothermic loophole" that penguins utilize in order to survive in Antarctica.<ref name="The heterothermic loophole exploited by penguins">{{cite journal|last1=Thomas|first1=D.B.|last2=Fordyce|first2=R.E.|title=The heterothermic loophole exploited by penguins|journal=Australian Journal of Zoology|date=2007|volume=55|issue=5|pages=317–321|doi=10.1071/zo07053}}</ref> 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.<ref name="Biological plasticity in penguin heat-retention structures">{{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}}</ref>

They can drink salt water because their ] filters excess salt from the bloodstream.<ref>{{cite web |url=http://www.zoo.org/educate/fact_sheets/penguin/penguin.htm |title=Animal Fact Sheets |accessdate=July 21, 2006 |url-status=dead |archiveurl=https://web.archive.org/web/20060720223700/http://www.zoo.org/educate/fact_sheets/penguin/penguin.htm |archivedate=July 20, 2006 |df=mdy-all }}</ref><ref>{{cite web |url=http://www.stlzoo.org/animals/abouttheanimals/birds/penguins/humboldtpenguin.htm |title=Humboldt Penguin: Saint Louis Zoo |accessdate=July 21, 2006 |url-status=dead |archiveurl=https://web.archive.org/web/20060928083710/http://www.stlzoo.org/animals/abouttheanimals/birds/penguins/humboldtpenguin.htm |archivedate=September 28, 2006 |df=mdy-all }}</ref><ref>{{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|accessdate=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}}</ref> The salt is excreted in a concentrated fluid from the nasal passages.

The ] 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 ].<ref> {{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.</ref>

===Isabelline penguins===
] ] on ].]]
Perhaps one in 50,000 penguins (of most species) are born with brown rather than black plumage. These are called ] 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.

==Distribution and habitat==
{{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 ]. In fact, only a few species of penguin actually live so far south. Several species live in the ] zone;<ref>{{cite web|url=http://www.birdlife.org/worldwide/news/list-penguin-species|accessdate=8 August 2016|title=List of Penguin Species|last=Askew|first=Nick|date=24 June 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}}</ref> one, the ], lives as far north as the ], but this is only made possible by the cold, rich waters of the Antarctic ] that flows around these islands.<ref>] (2007), ''Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals'', ].</ref> Also, though the climate of the Arctic and Antarctic regions is similar, there are no penguins found in the Arctic.<ref>{{cite book |title=Book: BSCS Biology, By Arnold Brams Grobman. | url=https://books.google.com/?id=xC-WGtA7eP8C&pg=PA36&dq=penguins+found+only+pole#v=onepage&q=penguins%20found%20only%20pole&f=false |isbn = 9780787290085|last1 = Grobman|first1 = Arnold Brams|year = 1964}}</ref>

Several authors have suggested that penguins are a good example of ]<ref>{{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 }}</ref><ref>{{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. |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 }}</ref> 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.<ref>{{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 }}</ref><ref>{{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 }}</ref>

Major populations of penguins are found in ], ], ], ], ], ], ], and ].<ref>{{cite web|archiveurl=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 |accessdate=8 September 2013|archivedate=February 17, 2012 }}</ref><ref>{{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 }}</ref> Satellite images and photos released in 2018 show the population of two million in ]'s remote ] has collapsed, with barely 200,000 remaining, according to a study published in Antarctic Science.<ref>{{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=2018-08-01|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}}</ref>

==Behaviour==
]s in ].]]

===Breeding===
{{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 watching over a sleeping chick at ]}}
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 a 100 pairs for gentoo penguins, to several hundred thousand in the case of king, macaroni and chinstrap penguins.<ref name=Will17>], p. 17</ref> 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.<ref name=Williams57>], p. 57</ref> ''Agonistic'' displays are those intended to confront or drive off, or alternately appease and avoid conflict with, other individuals.<ref name=Williams57/>

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 ]s, lay only one.<ref name=Will23>], p. 23</ref> With the exception of the emperor penguin, where the male does it all, all penguins share the ] duties.<ref>{{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}}</ref> 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.<ref>{{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}}</ref>

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%.<ref name=Will23/> 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.<ref>{{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}}</ref> 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.<ref name=Will24>], p. 24</ref>

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.<ref>{{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 |accessdate=9 March 2020 |work=BBC Earth |date=23 December 2015}}</ref> In some species, such as king and emperor penguins, the chicks assemble in large groups called ].

== Conservation status ==
The majority of living penguin species have declining populations. According to the IUCN Red List, their conservation statuses range from Least Concerned through to Endangered.
{| class="wikitable"
|-
! Species
!IUCN Red List Status
!Trend
!Mature Individuals
!Last assessment
|-
|], ''Aptenodytes forsteri''
|Near Threatened
|Unknown
|
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2004-05-01|title=IUCN Red List of Threatened Species: Emperor Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Aptenodytes patagonicus''
|Least Concern
|Increasing
|
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: King Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Eudyptula minor''
|Least Concern
|Stable
|469,760
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-08|title=IUCN Red List of Threatened Species: Little Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Eudyptes chrysocome''
|Vulnerable
|Decreasing
|2,500,000
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Southern Rockhopper Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Eudyptes chrysolophus''
|Vulnerable
|Decreasing
|
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Macaroni Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Eudyptes moseleyi''
|Endangered
|Decreasing
|480,600
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Northern Rockhopper Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Eudyptes pachyrynchus''
|Vulnerable
|Decreasing
|2,500-9,999
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Fiordland Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Eudyptes robustus''
|Vulnerable
|Stable
|63,000
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Snares Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Eudyptes schlegeli'' (disputed)
|Near Threatened
|Stable
|1,700,000
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Royal Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Eudyptes sclateri''
|Endangered
|Decreasing
|150,000
|2016<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2016-10-01|title=IUCN Red List of Threatened Species: Erect-crested Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Megadyptes antipodes''
|Endangered
|Decreasing
|2,528-3,480
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Yellow-eyed Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Pygoscelis adeliae''
|Least Concern
|Increasing
|7,580,000
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Adelie Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Pygoscelis antarctica''
|Least Concern
|Decreasing
|8,000,000
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-16|title=IUCN Red List of Threatened Species: Chinstrap Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Pygoscelis papua''
|Least Concern
|Stable
|774,000
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-07|title=IUCN Red List of Threatened Species: Gentoo Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Spheniscus demersus''
|Endangered
|Decreasing
|50,000
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-08|title=IUCN Red List of Threatened Species: African Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Spheniscus humboldti''
|Vulnerable
|Decreasing
|32,000
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-09|title=IUCN Red List of Threatened Species: Humboldt Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Spheniscus magellanicus''
|Near Threatened
|Decreasing
|
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-09|title=IUCN Red List of Threatened Species: Magellanic Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|-
|], ''Spheniscus mendiculus''
|Endangered
|Decreasing
|1,200
|2018<ref>{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2018-08-09|title=IUCN Red List of Threatened Species: Galapagos Penguin|url=https://www.iucnredlist.org/en|access-date=2020-06-02|website=IUCN Red List of Threatened Species}}</ref>
|}

==Penguins and humans==
] on the '']'' preparing an ] for consumption]]
] encounters a human during 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 ] or the nearby offshore islands. ]s preyed upon penguins while they were allowed in Antarctica during the age of early human exploration as ]s, but dogs have long since been banned from Antarctica.<ref> {{Webarchive|url=https://web.archive.org/web/20141113080747/http://www.antarctica.ac.uk/about_antarctica/environment/wildlife/removal_of_sledge_dogs.php |date=November 13, 2014 }}. British Antarctic Survey</ref> Instead, adult penguins are at risk at sea from predators such as ]s, ]s, and ]s. Typically, penguins do not approach closer than around 9 feet (3 meters), at which point they appear to become nervous.{{fact|date=February 2020}}

In June 2011, an Emperor penguin came ashore on New Zealand's Peka Peka Beach, 3200&nbsp;km off course on its journey to Antarctica.<ref>{{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}}</ref> Nicknamed Happy Feet, after the ] 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.<ref>{{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}}</ref> Happy Feet was a media sensation, with extensive coverage on TV and the web, including a live stream that had thousands of views<ref>{{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}}</ref> and a visit from English actor ].<ref>{{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}}</ref> Once he had recovered, Happy Feet was released back into the water south of New Zealand.<ref>{{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= VIDEO: Happy Feet starts the long journey home| 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}}</ref>

===In popular culture===
{{Main|Cultural depictions of penguins}}
] the ] mascot]]

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 ] suit. Some artists and writers have penguins based at the ], but there are no wild penguins in the ]. The cartoon series '']'' helped perpetuate this myth, as the title penguin would interact with Arctic or ] species, such as polar bears and walruses.

Penguins have been the subject of many books and films, such as '']'', '']'' and '']'', all ] films; '']'', a documentary based on the ] process of the ]; and a parody titled '']''. '']'' is a children's book written by Richard and Florence Atwater; it was named a ] in 1939. Penguins have also appeared in a number of cartoons and television dramas, including '']'', created by ] in 1986 and covering more than 100 short episodes. At the end of 2009, '']'' 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."<ref>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, {{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</ref>

A video game called '']'' was released by ] 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 ]. Several remakes and enhanced editions have followed, most recently in 2012. Penguins are also sometimes depicted in music.<ref>Shuker, R. (2012). ''Understanding popular music culture''. Routledge.</ref>

In 1941, ] introduced the avian-themed character of ] as a ] adversary of the ] ] (''Detective Comics'' #58). He became one of the most enduring enemies in Batman's rogue's gallery. In the 60s '']'' TV series, as played by ], he was one of the most popular characters, and in ]'s reimagining of the character in the 1992 film '']'', he employed an actual army of penguins (mostly ]).
Several pro, minor, college and high school sport teams in the ] have named themselves after the species, including the ] team in the ] and the ] in ].

Penguins featured regularly in the cartoons of UK cartoonist ] in his strip in '']'' newspaper, particularly during and following the ]. ], from the cartoons of ], is also described as hailing from the Falklands. Opus was a comical, "existentialist" penguin character in the cartoons '']'', '']'' and '']''. He was also the star in the Christmas show '']''.

In the mid-2000s, penguins became one of the most publicized species of animals that form lasting ]. A ], '']'', was written about ] in the ].

==References==

{{Reflist|30em|refs=
<ref name="Acosta">{{in lang|es}} Acosta Hospitaleche, Carolina (2004) {{Webarchive|url=https://web.archive.org/web/20140915050811/http://sedici.unlp.edu.ar/handle/10915/4286 |date=September 15, 2014 }}. Doctoral thesis, Department of Natural Sciences and Museum, Universidad Nacional de La Plata. La Plata, Argentina.</ref>

<ref name=Baker>{{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}}</ref>

<ref name="Banks">{{cite journal |author1=Banks, Jonathan C. |author2=Mitchell, Anthony D. |author3=Waas, Joseph R. |author4=Paterson, Adrian M. |lastauthoramp=yes |year=2002 |title=An unexpected pattern of molecular divergence within the blue penguin (''Eudyptula minor'') complex |journal=Notornis |volume=49 |issue=1 |pages=29–38 |url=http://www.notornis.org.nz/free_issues/Notornis_49-2002/Notornis_49_1_29.pdf |archive-url=https://web.archive.org/web/20070724203300/http://www.notornis.org.nz/free_issues/Notornis_49-2002/Notornis_49_1_29.pdf |url-status=dead |archive-date=2007-07-24 }}</ref>

<ref name="Clarke">{{cite journal |author1=Clarke, Julia A. |author2=Olivero, Eduardo B. |author3=Puerta, Pablo |lastauthoramp=yes |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 |volume=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 |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 }}</ref>

<ref name="Crofford10">{{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 = | url = https://archive.org/details/greatauk0000crof/page/10}}</ref>

<ref name="Davis & Renner">Davis; Lloyd S. & Renner; M. (1995). ''Penguins''. London: T & A D Poyser. {{ISBN|0-7136-6550-5}}</ref>

<ref name="Jadwiszczak">{{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}}</ref>

<ref name="Marples">Marples, B. J. (1962): Observations on the history of penguins. In: Leeper, G. W. (ed.), ''The evolution of living organisms''. Melbourne, ]. pp. 408–416.</ref>
}}

==Bibliography==
* {{cite book|ref= Williams|author1=Williams |author2=Tony D. |year=1995|title=The Penguins – Spheniscidae|place= Oxford|publisher= ]|isbn=978-0-19-854667-2}}

==External links==
{{Library resources box}}
{{Wikispecies|Sphenisciformes}}
{{Commons|Spheniscidae|Penguin}}
* . news.nationalgeographic.com
*
*
*
*
* on the Internet Bird Collection
*
* in ] the Encyclopedia of New Zealand
*
*
*

{{Penguins}}
{{Birds}}

{{Taxonbar|from=Q9147}}
{{Authority control}}

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Revision as of 20:32, 10 July 2020