• Afrikaans: pikkewyn
• Basque: pinguino
• Bosnian: pingvin
• Bulgarian: пингвин
• Catalan: pingüí
• Chinese: 企鹅, 企鵝 (qǐ'é)
• Croatian: pingvin
• Czech: tučňák,
• Danish: pingvin
• Dutch: pinguïn
• Esperanto: pingveno
• Finnish: pingviini
• French: manchot
• German: Pinguin
• Greek: πιγκουίνος
• Hungarian: pingvin
• Icelandic: mörgæs
• Italian: pinguino
• Japanese: ペンギン
• Korean: 펭귄 (p'eng-gwin)
• Lithuanian: pingvinas
• Low Saxon: Pinguien
• Macedonian: пингвин
• Maltese: pengwin
• Norwegian: pingvin
• Polish: pingwin
• Portuguese: pinguim / pingüim
• Romanian: pinguin, pinguini
• Russian: пингвин
• Serbian:

  Cyrillic: пингвин

  Latin: pingvin

• Slovene: pingvin
• Spanish: pingüino
• Swedish: pingvin
• Turkish: penguen

Penguins (order Sphenisciformes, family Spheniscidae) are a group of aquatic, flightless birds living almost exclusively in the Southern Hemisphere. The number of penguin species is debated. Depending on which authority is followed, penguin biodiversity varies between 17 and 20 living species, all in the subfamily Spheniscinae. Some sources consider the White-flippered Penguin a separate Eudyptula species, while others treat it as a subspecies of the Little Penguin; the actual situation seems to be more complicated. Similarly, it is still unclear whether the Royal Penguin is merely a color morph of the Macaroni penguin. Also eligible to be a separate species is the Northern population of Rockhopper penguins. this is used by parents and chicks to locate one another in crowded colonies. 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.

Penguins have a thick layer of insulating feathers which serve to keep them warm in water (heat loss in water is much greater than in air). The Emperor penguin (the largest 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 which 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 center of the heat pack.

They can drink salt water because their supraorbital gland filters excess salt from the bloodstream. The salt is excreted in a concentrated fluid from the nasal passages.

Breeding

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, though the two largest species, the Emperor and the King Penguins, lay only one. The parents cooperate in caring for the clutch and the young. During the cold season on the other hand the mates separate for several months to protect the egg. Usually, the male stays with the egg and keeps it warm while the female goes to sea to find food for the baby. When the female comes back, they switch roles.

Penguin eggs are smaller than any other bird species when compared proportionally to the weight of the parent birds; at 52 grams, the Little Penguin egg is 4.7% of its mothers' weight, and the 450-gram Emperor Penguin egg is 2.3%.

When 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. In some species, such as Emperor Penguins, young penguins assemble in large groups called crèches.

Isabelline penguins

Perhaps one in 50,000 penguins (of most species) are born with brown rather than black plumage. These are called Isabelline penguins, possibly in reference to the legend that the archduchess Isabella of Austria vowed not to change her undergarments until her husband united the northern and southern Low Countries by taking the city of Ostend – which took three years to accomplish. Isabellinism is different from albinism, though the faded color of the plumage calls albinism to mind. 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.

Systematics and evolution

Systematics

Updated after Marples (1962), Acosta Hospitaleche (2004), and Ksepka et al. (2006). See the gallery for images of most living species.

ORDER SPHENISCIFORMES

• Basal and unresolved taxa (all fossil)
  • Waimanu – basal (Middle-Late Paleocene)
  • Perudyptes (Middle Eocene of Atacama Desert, Peru) – basal?
  • Spheniscidae gen. et sp. indet. CADIC P 21 (Leticia Middle Eocene of Punta Torcida, Argentina: Clarke et al. 2003)
  • Delphinornis (Middle/Late Eocene? – Early Oligocene of Seymour Island, Antarctica) – Palaeeudyptinae, basal, new subfamily 1?
  • Archaeospheniscus (Middle/Late Eocene – Late Oligocene) – Palaeeudyptinae? New subfamily 2?
  • Marambiornis (Late Eocene –? Early Oligocene of Seymour Island, Antarctica) – Palaeeudyptinae, basal, new subfamily 1?
  • Mesetaornis (Late Eocene –? Early Oligocene of Seymour Island, Antarctica) – Palaeeudyptinae, basal, new subfamily 1?
  • Tonniornis (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)
  • Wimanornis (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)
  • Duntroonornis (Late Oligocene of Otago, New Zealand) – possibly Spheniscinae
  • Korora (Late Oligocene of S Canterbury, New Zealand)
  • Platydyptes (Late Oligocene of New Zealand) – possibly not monophyletic; Palaeeudyptinae, Paraptenodytinae or new subfamily?
  • Spheniscus gen. et sp. indet (Late Oligocene/Early Miocene of Hakataramea, New Zealand)
  • Madrynornis (Puerto Madryn Late Miocene of Argentina) – possibly Spheniscinae
  • Pseudaptenodytes (Late Miocene/Early Pliocene)
  • Dege (Early Pliocene of South Africa) – possibly Spheniscinae
  • Marplesornis (Early Pliocene) – possibly Spheniscinae
  • Nucleornis (Early Pliocene of Duinfontain, South Africa) – possibly Spheniscinae
  • Inguza (Late Pliocene) – probably Spheniscinae; formerly Spheniscus predemersus
• Family Spheniscidae
  • Subfamily Palaeeudyptinae – Giant penguins (fossil)
    • Crossvallia (Cross Valley Late Paleocene of Seymour Island, Antarctica) – tentatively assigned to this subfamily
    • Anthropornis (Middle Eocene? – Early Oligocene of Seymour Island, Antarctica) – tentatively assigned to this subfamily
      • Nordenskjoeld's Giant Penguin, Anthropornis nordenskjoeldi
    • Icadyptes (Late Eocene of Atacama Desert, Peru)
    • Palaeeudyptes (Middle/Late Eocene – Late Oligocene) – polyphyletic; some belong in other subfamilies
    • Pachydyptes (Late Eocene)
    • Anthropodyptes (Middle Miocene) – tentatively assigned to this subfamily
  • Subfamily Paraptenodytinae – Stout-footed penguins (fossil)
    • Arthrodytes (San Julian Late Eocene/Early Oligocene – Patagonia Early Miocene of Patagonia, Argentina)
    • Paraptenodytes (Early – Late Miocene/Early Pliocene)
  • Subfamily Palaeospheniscinae – Slender-footed penguins (fossil)
    • Eretiscus (Patagonia Early Miocene of Patagonia, Argentina)
    • Palaeospheniscus (Early? – Late Miocene/Early Pliocene) – includes Chubutodyptes
  • Subfamily Spheniscinae – Modern penguins
    • Aptenodytes – Great penguins (2 species)
    • Pygoscelis – Brush-tailed penguins (3 species)
    • Eudyptula – Little penguins (1 or 2 species)
    • Spheniscus – Banded penguins (4 species)
    • Megadyptes – Yellow-eyed Penguin
    • Eudyptes – Crested penguins (6–8 living species)

Taxonomy: Clarke et al. (2003) and Ksepka et al. (2006) 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 seems spurious and in any case is confusing; the established Linnean system is thus followed here.

Evolution

The evolutionary history of penguins is well-researched and represents a showcase of evolutionary biogeography; though as penguin bones of any one species vary much in size and few good specimens are known, the alpha taxonomy of many prehistoric forms still leaves much to be desired. Some seminal articles about penguin prehistory have been published since 2005, the evolution of the living genera can be considered resolved by now.

The basal penguins lived around the time of the Cretaceous–Tertiary extinction event somewhere in the general area of (southern) New Zealand and Byrd Land, Antarctica. What can be said as certainly as possible in the absence of direct (i.e., fossil) evidence is that by the end of the Cretaceous, the penguin lineage must have been evolutionarily well distinct, though much less so morphologically; 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 trophic webs which follows the initial phase of mass extinctions because of their below-average dispersal capabilities (see also Flightless Cormorant).

The basal fossils

The oldest known fossil penguin species is Waimanu manneringi, which lived in the early Paleocene epoch of New Zealand, or about 62 mya. primitive penguins had spread to South America and were in the process of expanding into Atlantic waters. It is not even known whether the gigantic palaeeudyptines constitute a monophyletic 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 Anthropornis nordenskjoeldi). but the range expansion and radiation which 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.

Inside this group, penguin relationships are far less clear. Depending on the analysis and dataset, a close relationship to Ciconiiformes

The Auk of the Northern Hemisphere is superficially similar to penguins: they are not related to the penguins at all, but considered by some to be a product of moderate convergent evolution.

Penguins and humans

Etymology

The word Penguin is thought by some to derive from the Welsh words pen (head) and gwyn (white), applied to the Great Auk which had white spots in front of its eyes (although its head was black); or from an island off Newfoundland known as Pengwyn, due to its having a large white rock. (In the latter case, the name may also have come from Breton.) This theory is supported by the fact that penguins look remarkably like Great Auks in general shape.

It is also possible that penguin comes from the Latin pinguis, “fat”. This is supported by the fact that the corresponding words in most other languages (e.g., French pingouin, German Pinguin) have i instead of e as the first vowel. However, a Welsh i is often sound-shifted to an e in the English language.

Another theory states that the word is an alteration of “pen-wing”, with reference to the rudimentary wings of both Great Auks and penguins, but there is no evidence to support this.

What may be a King Penguin but certainly is a member of the Spheniscidae appears on a 1599 map at the Strait of Magellan with the caption "Pinguyn". The map's features are labeled in Latin, such as Fretum Magellanicum ("Strait of Magellan"). In addition, there is ample evidence that the Latin term anser magellanicus ("Goose of Magellan" or "Magellanic Goose") was the usual term for penguins in the scholarly literature of that time. If the English word was derived from Latin – e.g. avis pinguis ("fat bird") or pinguinus ("the fat one") – it must have originated considerably earlier than 1600.

In a final twist to the story, the term "Magellanic Goose" (today usually "Magellan Goose") in our time has come to denote an actual anseriform, namely a Chloephaga sheldgoose.

Penguins in popular culture

Penguins are popular around the world, primarily for their unusually upright, waddling gait and (compared to other birds) lack of fear of humans. Their striking black-and-white plumage is often likened to a tuxedo suit. Mistakenly, some artists and writers have penguins based at the North Pole. This is incorrect, as there are almost no wild penguins in the northern hemisphere, except the small group on the northernmost of the Galápagos.

Penguins have been the subject of many books and films such as Happy Feet and Surf's Up, both CGI films; March of the Penguins, a documentary based on the migration process of Emperors; and a parody entitled Farce of the Penguins. Penguins have also found their way into a number of cartoons and television dramas; perhaps the most notable of these is Pingu, created by Silvio Mazzola in 1986 and covering more than 100 short episodes.

In the mid-2000s, penguins became one of the most publicised species of animals that formed lasting homosexual couples.

Species photographs

Photographs of the adults of living species are show:

General gallery

References

Footnotes

Bibliography

• Two new fossil penguin species found in Peru
• Acosta Hospitaleche, Carolina (2004): Los pingüinos (Aves, Sphenisciformes) fósiles de Patagonia. Sistemática, biogeografía y evolución. Doctoral thesis, Department of Natural Sciences and Museum, Universidad Nacional de La Plata. La Plata, Argentina. [in Spanish] PDF fulltext
• Baker, Allan J.; Pereira, Sergio Luiz; Haddrath, Oliver P. & Edge, Kerri-Anne (2006): Multiple gene evidence for expansion of extant penguins out of Antarctica due to global cooling. Proc. R. Soc. B 273: 11-17. PDF fulltext
• Banks, Jonathan C.; Mitchell, Anthony D.; Waas, Joseph R. & Paterson, Adrian M. (2002): An unexpected pattern of molecular divergence within the blue penguin (Eudyptula minor) complex. Notornis 49(1): 29–38. PDF fulltext
• Bertelli, Sara & Giannini, Norberto P. (2005): A phylogeny of extant penguins (Aves: Sphenisciformes) combining morphology and mitochondrial sequences. Cladistics 21(3): 209–239. (HTML abstract)
• Clarke, Julia A.; Olivero, Eduardo B. & Puerta, Pablo (2003): Description of the earliest fossil penguin from South America and first Paleogene vertebrate locality of Tierra Del Fuego, Argentina. American Museum novitates 3423: 1-18. PDF fulltext
• Davis; Lloyd S. & Renner; M. (1995). Penguins . London: T & A D Poyser. ISBN 0-7136-6550-5
• Fain, Matthew G. & Houde, Peter (2004): Parallel radiations in the primary clades of birds. Evolution 58(11): 2558-2573. PDF fulltext
• Jadwiszczak, Piotr (2006): Eocene penguins of Seymour Island, Antarctica: taxonomy. Polish Polar Research 27(1), 3–62. PDF fulltext
• Jouventin, P; Aubin, T. & T Lengagne (1999) "Finding a parent in a king penguin colony: the acoustic system of individual recognition" Animal Behaviour 57: 1175–1183 http://www.cb.u-psud.fr/animbehavkp.pdf
• Ksepka, Daniel T., Bertelli, Sara & Giannini, Norberto P. (2006): The phylogeny of the living and fossil Sphenisciformes (penguins). Cladistics 22(5): 412–441. (HTML abstract)
• Marples, B. J. (1962): Observations on the history of penguins. In: Leeper, G. W. (ed.), The evolution of living organisms. Melbourne, Melbourne University Press: 408-416.
• Mayr, G. (2005): Tertiary plotopterids (Aves, Plotopteridae) and a novel hypothesis on the phylogenetic relationships of penguins (Spheniscidae). Journal of Zoological Systematics and Evolutionary Research 43(1): 61-71. PDF fulltext
• Sivak, J.; Howland, H. & McGill-Harelstad, P. (1987) "Vision of the Humboldt Penguin (Spheniscus humboldti) in Air and Water " Proceedings of the Royal Society of London. Series B, Biological Sciences. 229(1257): 467-472
• Slack, Kerryn E.; Jones, Craig M.; Ando, Tatsuro; Harrison G. L. "Abby"; Fordyce R. Ewan; Arnason, Ulfur & Penny, David (2006): Early Penguin Fossils, plus Mitochondrial Genomes, Calibrate Avian Evolution. Molecular Biology and Evolution 23(6): 1144-1155. PDF fulltext Supplementary Material
• Wever, E.; Herman, P.; Simmons, J. & Hertzler D (1969) "Hearing in the Blackfooted Penguin, Spheniscus demersus, as Represented by the Cochlear Potentials" PNAS 63(3): 676-680 http://www.pnas.org/cgi/reprint/63/3/676
• Williams; Tony D. (1995). The Penguins - Spheniscidae . Oxford: Oxford University Press. ISBN 0-19-854667-X

External links

• Penguin World
• penguinpage.net - Penguin research projects on the web
• Penguin information on 70South
• Information about penguins at pinguins.info
• PBS Nature: The World of Penguins
• Integrated Taxonomic Information System
• Seaworld Penguin Information
• Penguin Videos on the Internet Bird Collection