Penguin Habitat

Penguins (order Sphenisciformes , family Spheniscidae ) are a group of aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapted for life in the water, penguins have countershaded dark and white plumage and flippers for swimming. Most penguins feed on krill, fish, squid and other forms of sea life which they catch with their bills and swallow it whole while swimming. A penguin has a spiny tongue and powerful jaws to grip slippery prey.

They spend roughly half of their lives on land and the other half in the sea.

The largest living species is the emperor penguin (''Aptenodytes forsteri''): on average, adults are about tall and weigh . The smallest penguin species is the little blue penguin (''Eudyptula minor''), also known as the fairy penguin, which stands around tall and weighs . Today, larger penguins generally inhabit colder regions, and smaller penguins inhabit regions with temperate or tropical climates. Some prehistoric penguin species were enormous: as tall or heavy as an adult human. There was a great diversity of species in subantarctic regions, and at least one giant species in a region around 2,000 km south of the equator 35 mya, during the Late Eocene, a climate decidedly warmer than today.

Etymology

The word ''penguin'' first appears in literature at the end of the 16th century. 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, Breton or Spanishpingüino
. Diccionario de la lengua española. rae.es origin (the latter two are attributed to the French word ), but first appears in English or Dutch.

Some dictionaries suggest a derivation from Welsh , "head" and , "white", including the '' Oxford English Dictionary'', the '' American Heritage Dictionary'', the '' Century Dictionary'' and ''Merriam-Webster'', on the basis that the name was originally applied to the great auk, either because it was found on White Head Island ( 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 Latin , which means "fat" or "oil". Support for this etymology can be found in the alternative Germanic word for penguin, or "fat-goose", and the related Dutch word .

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

Pinguinus

Since 1871, the Latin word ''Pinguinus'' has been used in scientific classification to name the genus of the great auk (''Pinguinus impennis'', meaning "penguin without flight feathers"), 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.

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 Bonaparte in several distinct genera within the family Spheniscidae and order Sphenisciformes.

Systematics and evolution

Living and recently extinct species

The number of extinct 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 blue penguin; WilliamsDavis; Lloyd S. & Renner; M. (1995). '' Penguins''. London: T & A D Poyser. the actual situation seems to be more complicated. Similarly, it is still unclear whether the royal penguin is a separate species or merely a color morph of the macaroni penguin. The status of the rockhopper penguins is also unclear.

Updated after Marples (1962), Acosta Hospitaleche (2004), and Ksepka ''et al.'' (2006).

Subfamily Spheniscinae – modern penguins

Fossil genera

Order Sphenisciformes
* Basal and unresolved taxa (all fossil)
** ''Anthropodyptes'' (Middle Miocene)
** '' Arthrodytes'' (San Julian Late Eocene/Early Oligocene – Patagonia Early Miocene of Patagonia, Argentina)
** '' Aprosdokitos'' Hospitaleche, Reguero & Santillana 2017
** '' Crossvallia'' (Cross Valley Late Paleocene of Seymour Island, Antarctica)
** '' Ichthyopteryx'' Wiman 1905
** '' Kupoupou'' (Late Early-Middle Paleocene of Takatika Grit, New Zealand)
** '' Kaiika'' Fordyce & Tomas 2011 (Maxwell's penguin)
** '' Korora'' (Late Oligocene of S Canterbury, New Zealand)
** '' Inguza'' (Late Pliocene)
** '' Muriwaimanu'' (Late Paleocene of Canterbury, New Zealand)
** '' Nucleornis'' (Early Pliocene of Duinfontain, South Africa)
** '' Orthopteryx'' Wiman 1905
** ''Palaeoapterodytes'' (Late Oligocene/Early Miocene of Argentina)
** ''Pseudaptenodytes'' (Late Miocene/Early Pliocene)
** '' Sequiwaimanu'' (Late Paleocene)
** '' Tasidyptes'' Van Tets & O'Connor 1983 nomen dubium (Hunter Island penguins)
** ''Tereingaornis'' (Middle Pliocene of New Zealand)
** '' Tonniornis'' (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)
** '' Wimanornis'' (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)
* Spheniscidae
** '' Waimanu'' Jones, Ando & Fordyce 2006 (Middle-Late Paleocene)
** '' Kumimanu'' Mayr, 2017
** '' Delphinornis'' Wiman 1905 (Middle/Late Eocene? – Early Oligocene of Seymour Island, Antarctica)
** '' Marambiornis'' Myrcha et al. 2002 (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)
** '' Mesetaornis'' Myrcha et al. 2002 (Late Eocene –? Early Oligocene of Seymour Island, Antarctica)
** ''Perudyptes