Penguin

From Freepedia

For other uses, see Penguin (disambiguation).
Penguins
Image:Manchot 01.jpg
Chinstrap Penguin, Pygoscelis antarctica
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Sphenisciformes
Sharpe, 1891
Family:Spheniscidae
Bonaparte, 1831
Genera

Aptenodytes
Eudyptes
Eudyptula
Megadyptes
Pygoscelis

Spheniscus

Penguins (order Sphenisciformes, family Spheniscidae) are an order of flightless birds living in the southern hemisphere.

Contents

Species and habitats

There are 17 or 18 known species worldwide, depending on whether the two Eudyptula species are counted as distinct. Although all penguin species are native to the southern hemisphere, they are not, contrary to popular belief, found only in cold climates, such as Antarctica. In fact, only a few species of penguin actually live so far south. Three species live in the tropics; one lives as far north as the Galapagos Islands and will occasionally cross the equator while feeding.

The largest species is the Emperor Penguin (Aptenodytes forsteri): adults average about 1.1 meters (3 ft 7 in) tall and weigh 35 kilograms (75 lb) or more. The smallest penguin species is the Little Blue Penguin (also known as the Fairy Penguin), which stands around 40 cm tall (16 in) and weighs 1 kilogram (2.2 lb). Generally larger penguins retain heat better, and thus inhabit colder regions, while smaller penguins are found in temperate or even tropical climates.

Penguins are gregarious. Most feed on krill, fish, squid, and other forms of sealife caught while swimming underwater. They spend half of their life on land and half in the oceans.

Evolution

Penguins are actually very old birds. The oldest fossils of penguins emerged in the Eocene era more than 40 million years ago. However these fossils proved that prehistoric penguins were already flightless and seagoing, so their origins may go as far back as 65 million years ago. Had the dinosaurs not died out, penguins could look like this [1]. With no more giant marine reptiles and prehistoric marine birds like Hesperornis, penguins diversified. During the Eocene, penguins had no competition as top aquatic predators. Some extinct penguins grew larger than humans. Birds like Palaeeudyptes from the Eocene, Pachydyptes from the Miocene and the now extinct Great Auks resembled modern penguins. The links between other bird orders and penguins are still unknown, and though a close relationship between penguins, Procellariiformes and Gaviiformes is usually assumed, it has not been proved and some anatomical evidence has been interpreted as supporting a placement of Spheniscidae within a group of birds classified as Pelecaniformes. Most fossil penguins known are large, but not larger than the modern Emperor Penguin. This size is maintained because at the time, there were no marine mammals so far south. By the Miocene and Pliocene, marine mammals colonized the southern hemisphere, wiping out a vast majority of the penguins at the time. Only 17 species survived, dwarfs compared to the fallen giants so long ago. All lived in the southern hemisphere.

Anatomy

Penguins are superbly adapted to an aquatic life. Their wings have become flippers, useless for flight in the air. In the water, however, penguins are astonishingly agile. Within the smooth plumage a layer of air is preserved, ensuring buoyancy. The air layer also helps insulate the bird in the icy waters of the Antarctic. The plumage of penguins in tropical and temperate zones is much thinner.

On land, penguins use their tails and wings to maintain balance for their upright stance.

All penguins have a white underside and a dark (mostly black) upperside. This is for camouflage. A predator looking up from below (such as an orca or a leopard seal) has difficulty distinguishing between a white penguin belly and the reflective water surface.

Diving penguins reach 6 to 12 km/h, though there are reports of velocities of 27 km/h (which are probably realistic in the case of startled flight). 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. The Emperor Penguin has been recorded reaching a depth of 875 feet (270 metres) and staying submerged for 18 minutes.

On land, penguins are clumsy. They either waddle on their feet or slide on their bellies across the snow, a movement called "tobogganing", which allows them to conserve energy and move relatively fast at the same time.

Penguins have an excellent sense of hearing. Their eyes are adapted for underwater vision, and are their primary means of locating prey and avoiding predators; in air, conversely, they are nearsighted. Their sense of smell has not been researched so far.

They are able to drink salt water safely, because a gland near their eyes filters excess salt from the bloodstream. The salt is excreted in a concentrated fluid from the nasal passages.

Penguins have no external genitalia.[2] Consequently, chromosome testing must be done in order to determine a penguin's sex.

Sexuality and mating habits

Most penguins mate for life. They generally raise a small brood, and the parents co-operate in caring for the clutch and for the young.

Male penguin couples have also been documented. They too mate for life and build nests together. Male couples have been recorded using a stone to replace sitting on an egg in the nest. In 2004, the Central Park Zoo in the United States replaced one male couple's stone with a fertile egg which they then raised as their own offspring [3]. This was the basis for the children's picture book And Tango Makes Three. The couple about whom the book was based, Silo and Roy, would see further interesting (if not unfortunate) developements in their relationship when, in September 2005, Silo left Roy, as well as their adopted chick, for a female penguin. Homosexuality among penguins has also been reported by Germany's Bremerhaven Zoo-Am-Meer and Kelly Tarlton's Aquarium in Auckland, New Zealand. [4]

Gallery

Adelie penguin in Antarctica

African or Jackass Penguin

Chinstrap Penguin hunting for krill

Squawk and Milou, male Chinstrap Penguins, one of several homosexual pairs at the Central Park Zoo in Manhattan

Humboldt Penguin and eggs

Magellanic penguin

Classification

ORDER SPHENISCIFORMES

Name

Penguin is thought by some to derive from the Welsh words pen (head) and gwyn (white), applied to the Great Auk, which had a conspicuous white patch between the bill and the eye (although its head was black), or from an island off Newfoundland known as "White Head" due to a large white rock. According to another theory, the original name was pen-wing, with reference to the rudimentary wings of both Great Auks and penguins. A third theory is that penguin comes from the Latin pinguis (fat).

Penguins in popular culture

Penguins are popular around the world primarily for their unusually upright, waddling pace and (compared to other birds) lack of fear towards humans. Their striking black and white plumage is often likened to a tuxedo suit and generates humourous remarks about the bird being "well dressed".

Perhaps in reaction to this cutesy stereotype, fictional penguins are occasionally presented as grouchy or even sinister. The popular Sanrio character Badtz Maru is an example, being cute yet somewhat surly. Feathers McGraw is a wanted criminal. The 1960s television cartoon character Tennessee Tuxedo would often escape the confines of his zoo with his partner, Chumley the walrus. Also, the webcomic Fluble features an enormous penguin conspiracy run by numerous diabolical, if often inept, penguins.

Computing

  • Sega's 1982 video-game Pengo stars a penguin.
  • A penguin is a main character in a number of 1980s Konami games, and shows up as a mascot in others.
  • Penguins are featured in the computer game Pingus, similar to the classic computer game Lemmings.
  • Penguins feature prominently in the popular Yetisports series of Flash games.
  • The Linux mascot Tux is a penguin, and is featured in several computer games, such as Tux Racer.
  • The Gentoo Linux distribution is named after the Gentoo Penguin.
  • The Nintendo 64 game "Mario 64" features a level in which a mother and baby penguin are prominent characters.
  • The penguin appears in a recent edition of the video game Pitfall. In fact, one part of the game involves fighting the protagonist as a penguin. Strangely unlike the typical South American penguins, the penguins from Pitfall have crests like the crested penguins.
  • The website War Of The Penguins.com is one of several sites that talk about "evil penguins." The website concentrates on the military invasion of the world by a hypothetical Penguin Army.

Politics

Comics

Film

Literature

  • The children's book Mr. Popper's Penguins details Mr. Popper and his 12 performing penguins.
  • Three children's books by Janet Perlman--Cinderella Penguin, The Emperor Penguin's New Clothes, and The Penguin and the Pea--retell classic children's stories with a penguin twist.

Sports mascots

Places

Penguin, Tasmania is a town in Tasmania, Australia, located at 41° 7′ 0″ S, 146° 4′ 15″ E (Map Quest).

Audio CDs

  • Frobisher, the talking alien penguin from the DWM comics, has appeared in several of the licensed Doctor Who audio plays produced by Big Finish, including The Holy Terror and The Maltese Penguin.
  • Sack Trick's second album, Penguins on the Moon, is the tale of four heroic penguins who journeyed to the moon in search of a more habitable climate.
  • dredg's fifth album "El Cielo" features a song called "Triangle" with repetitious lyrics asking "We live like Penguins in the desert, why can't we live like tribes?"

External links

Retrieved from "http://en.freepedia.org/Penguin.html"


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