“Gentoo penguin”的意思、由来-开放百科全书

The gentoo penguin ({{IPAc-en|ˈ|dʒ|ɛ|n|t|uː}} {{respell|JEN|too}}) (Pygoscelis papua) is a penguin species in the genus Pygoscelis, most closely related to the Adélie penguin (P. adeliae) and the chinstrap penguin (P. antarcticus). The earliest scientific description was made in 1781 by Johann Reinhold Forster with a reference point of the Falkland Islands. They call in a variety of ways, but the most frequently heard is a loud trumpeting which the bird emits with its head thrown back.^[2]

Names

The application of gentoo to the penguin is unclear. Gentoo was an Anglo-Indian term to distinguish Hindus from Muslims. The English term may have originated from the Portuguese gentil ("pagan, gentile"). Some speculate that the white patch on the bird's head was thought to resemble a turban.^[3]

It may also be a variation of another name for this bird, "Johnny penguin", Johnny being {{lang|es|Juanito}} in Spanish and sounds vaguely like gentoo.^[3]^[4]^[5] The Johnny rook, a predator, is likely named after the Johnny penguin.^[6]

The specific name papua is a misnomer; in the original description, Johann Reinhold Forster, a naturalist who had circumnavigated the world with Captain James Cook, mistakenly assumed that the species occurred in Papua (New Guinea), the closest gentoos actually being over 6000 km to the south (on Macquarie Island).^[7] There are no penguins in New Guinea, however.^[8] Others trace the error to a "possibly fraudulent claim" in 1776 by French naturalist Pierre Sonnerat, who also alleged a Papuan location for the king penguin despite never having been to the island himself.^[9]

Taxonomy

The gentoo penguin is one of three species in the genus Pygoscelis. Mitochondrial and nuclear DNA evidence suggests the genus split from other penguins around 38 million years ago, about 2 million years after the ancestors of the genus Aptenodytes. In turn, the Adelie penguins split off from the other members of the genus around 19 million years ago, and the chinstrap and gentoo finally diverged around 14 million years ago.^[10]

Two subspecies of this penguin are recognised: Pygoscelis papua papua and the smaller Pygoscelis papua ellsworthi.

Description

The gentoo penguin is easily recognized by the wide white stripe extending like a bonnet across the top of its head and its bright orange-red bill. It has pale whitish-pink webbed feet and a fairly long tail – the most prominent tail of all penguin species. Chicks have grey backs with white fronts. As the gentoo penguin waddles along on land, its tail sticks out behind, sweeping from side to side, hence the scientific name Pygoscelis, which means "rump-tailed".^[11]

Gentoos reach a height of {{Convert|51|to|90|cm|abbr = on}},^[12]^[13] making them the third-largest species of penguin after the emperor penguin and the king penguin. Males have a maximum weight of about {{Convert|8.5|kg|abbr = on}} just before molting, and a minimum weight of about {{Convert|4.9|kg|abbr = on}} just before mating. For females, the maximum weight is {{Convert|8.2|kg|abbr = on}} just before molting, but their weight drops to as little as {{Convert|4.5|kg|abbr = on}} when guarding the chicks in the nest.^[14] Birds from the north are on average {{Convert|700|g|lb|abbr = on}} heavier and {{Convert|10|cm|abbr = on}} taller than the southern birds. Southern gentoo penguins reach {{convert|75|–|80|cm|in|abbr=on}} in length.^[15] They are the fastest underwater swimmers of all penguins, reaching speeds of up to {{Convert|36|km/h|abbr = on}}.^[16] Gentoos are well adapted to extremely cold and harsh climates.

Breeding

The breeding colonies of gentoo penguins are located on ice-free surfaces. Colonies can be directly on the shoreline or can be located considerably inland. They prefer shallow coastal areas and often nest between tufts of grass. In South Georgia, for example, breeding colonies are 2 km inland. Whereas in colonies farther inland, where the penguins nest in grassy areas, they shift location slightly every year because the grass will become trampled over time.

Gentoos breed on many sub-Antarctic islands. The main colonies are on the Falkland Islands, South Georgia and the South Sandwich Islands, and Kerguelen Islands; smaller colonies are found on Macquarie Island, Heard Islands, South Shetland Islands, and the Antarctic Peninsula. The total breeding population is estimated to be over 600,000 birds. Gentoos breed monogamously, and infidelity is typically punished with banishment from the colony.^[17] Nests are usually made from a roughly circular pile of stones and can be quite large, {{Convert|20|cm|abbr = on}} high and {{Convert|25|cm|abbr = on}} in diameter. The stones are jealously guarded and their ownership can be the subject of noisy disputes and physical attacks between individuals. They are also prized by the females, even to the point that a male penguin can obtain the favors of a female by offering her a choice stone.

Two eggs are laid, both weighing around {{Convert|130|g|abbr = on}}. The parents share incubation, changing duty daily. The eggs hatch after 34 to 36 days. The chicks remain in the nests for around 30 days before joining other chicks in the colony and forming crèches. The chicks molt into subadult plumage and go out to sea at around 80 to 100 days.

Diet

Gentoos live mainly on crustaceans, such as krill, with fish making up only about 15% of the diet. However, they are opportunistic feeders, and around the Falklands are known to take roughly equal proportions of fish (Patagonotothen sp., Thysanopsetta naresi, Micromesistius australis), squat lobsters (Munida gregaria), and squid (Loligo gahi, Gonatus antarcticus, Moroteuthis ingens).

Physiology

The Gentoos' diet is high in salt as they eat organisms with relatively the same salinity as sea water, and this can lead to complications associated with high sodium concentrations in the body, especially for Gentoo chicks. To counteract this, Gentoos as well as many other marine bird species have a highly developed salt gland located above their eyes that takes the high concentration of sodium within the body and produces a highly saline-concentrated solution that drips out of the body from the tip of the beak.^[18]

Gentoo penguins do not store as much fat as the Adelie penguin, their closest relative: Gentoos require less energy investment when hunting because the net gain of energy after hunting is greater in Gentoos than Adelies.^[19] As embryos, Gentoos require a lot of energy in order to develop. Oxygen consumption is high for a developing Gentoo embryo. As the embryo grows and requires more oxygen, the amount of consumption increases exponentially until the gentoo chick hatches. By then, the chick is consuming around 1800 mL O₂ per day.^[20]

Predators

In the sea, leopard seals, sea lions, and killer whales are all predators of the Gentoo. On land, no predators of full-grown healthy Gentoo penguins exist. Skuas and giant petrels regularly kill many chicks and steal eggs; Petrels will kill injured and sick adult Gentoos. Various other seabirds, such as the kelp gull and snowy sheathbill, will also snatch chicks and eggs. Skuas on King George Island have been observed attacking and injuring adult Gentoo penguins in apparent territorial disputes.^[21]

Conservation status

Gallery

References

1. ^¹BirdLife International (2018). Pygoscelis papua. The IUCN Red List of Threatened Species 2018. {{doi|10.2305/IUCN.UK.2018-2.RLTS.T22697755A132600694.en}}
2. ^Woods, R.W. (1975) Birds of the Falkland Islands, Antony Nelson, Shropshire, UK.
3. ^{{cite book|last=Chester|first=Jonathan|title=Penguins: Birds of Distinction|url=https://books.google.com/books?id=6HIXAQAAIAAJ|year=1996|publisher=Penguin Books|location=Australia|isbn=978-0-14-025968-1|page=42|quote= Until the 1930s the gentoo was generally known in the Falklands as the Johnny penguin.}}
4. ^{{cite dictionary |title=gentoo penguin |dictionary=American Heritage Dictionary of the English Language |edition=5 |url=https://www.thefreedictionary.com/gentoo+penguin}}
5. ^{{cite book|last=Beaglehole|first=J.C.|authorlink=J.C. Beaglehole|title=The Journals of Captain James Cook on his Voyages of Discovery|url=https://books.google.com/books?id=XCQxDwAAQBAJ&pg=PT910|volume=II|year=2017|publisher=Taylor & Francis|isbn=978-1-351-54324-8|page=910|quote= In the eighteenth century English-speaking sealers commonly called [the gentoo] the Johnny Penguin. The Spanish translation of this was 'Juanito', which has degenerated into Gentoo.}}
6. ^{{cite book|last=Gorman|first=James|title=The Total Penguin|url=https://books.google.com/books?id=2TVHAAAAYAAJ|year=1990|publisher=Prentice Hall|isbn=978-0-13-925041-5|page=87|quote= Sealers called it the "Johnny penguin" or "John penguin." In that incarnation, it seems to have given its name to the striated caracara, a bird of prey that feeds on young gentoo penguins in the Falklands and is called the "Johnny rook."}}
7. ^¹{{cite book|last=Campbell|first=David G.|title=The Crystal Desert: Summers in Antarctica|url=https://books.google.com/books?id=E-p9KuhqhPUC&pg=PT278|year=2002|publisher=Houghton Mifflin Harcourt|isbn=978-0-547-52761-1|page=278}}
8. ^{{cite book|last=Troelstra|first=Anne S.|title=Bibliography of Natural History Travel Narratives|url=https://books.google.com/books?id=HaclDwAAQBAJ&pg=PA411|year=2017|publisher=Brill|isbn=978-90-04-34378-8|pages=411–}}
9. ^{{cite book|last1=Gray|first1=Jeannie|last2=Fraser|first2=Ian|title=Australian Bird Names|url=https://books.google.com/books?id=W1TCqHVWQp0C&pg=PT42|year=2013|publisher=Csiro|isbn=978-0-643-10471-6|page=42}}
10. ^{{cite journal |vauthors=Baker AJ, Pereira SL, Haddrath OP, Edge KA |year=2006|title=Multiple gene evidence for expansion of extant penguins out of Antarctica due to global cooling |journal=Proc Biol Sci |volume=273 |issue=1582|pages=11–17|doi=10.1098/rspb.2005.3260 |pmid=16519228 |pmc=1560011}}
11. ^{{cite web|url=http://www.arkive.org/gentoo-penguin/pygoscelis-papua/|archive-url=https://web.archive.org/web/20090520085242/http://www.arkive.org/gentoo-penguin/pygoscelis-papua/|dead-url=yes|archive-date=2009-05-20|title=Gentoo penguin videos, photos and facts – Pygoscelis papua|author=|date=|website=Arkive}}
12. ^{{cite web|url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Pygoscelis_papua.html|title=Pygoscelis papua (gentoo penguin)|author=|date=|website=Animal Diversity Web}}
13. ^{{Cite web |url=http://ourworld.compuserve.com/homepages/peter_and_Barbara_Barham/GENTOO.htm |title=Gentoo Penguin – Pygoscelis Papua |access-date=2008-09-23|author=Barham, Peter and Barham, Barbara |archive-url=https://web.archive.org/web/20080920031831/http://ourworld.compuserve.com/homepages/Peter_and_Barbara_Barham/gentoo.htm |archive-date=2008-09-20 |dead-url=yes |df= }}
14. ^{{cite web|url=http://www.arkive.org/species/GES/birds/Pygoscelis_papua/more_info.html?section=factsAndStatus|archive-url=https://archive.today/20120718020909/http://www.arkive.org/species/GES/birds/Pygoscelis_papua/more_info.html?section=factsAndStatus|dead-url=yes|archive-date=2012-07-18|title=Gentoo penguin videos, photos and facts – Pygoscelis papua|author=|date=|website=Arkive}}
15. ^{{cite web|url=http://www.coolantarctica.com/Antarctica%20fact%20file/wildlife/gentoo_penguin.htm|title=Antarctica fact file wildlife, gentoo penguins|author=|date=|website=coolantarctica.com}}
16. ^{{cite web|url=https://web.archive.org/web/20120205133021/http://www.bbc.co.uk/nature/life/Gentoo_Penguin|title=Gentoo penguin|work=BBC Nature }}
17. ^{{Cite journal |last=Trather |first=PN |last2=Forcada |first2=J |last3=Atkinson |first3=R |last4=Downie |first4=RH |last5=Shears |first5=JR |date=December 2008 |title=Population assessments of gentoo penguins (Pygoscelis papua) breeding at an important Antarctic tourist site, Goudier Island, Port Lockroy, Palmer Archipelago, Antarctica |journal=Biological Conservation |volume=141 |issue=12 |pages=3019–3028 |quote="Breeding pairs of Pygoscelis papua remained constant throughout the 1996/1997 breeding season. Males observed attempting to breed outside of their original breeding pair were violently rejected from the colony." |doi=10.1016/j.biocon.2008.09.006 }}
18. ^{{cite journal|author=Schmidt-Nielsen, K. |title=The Salt-Secreting Gland of Marine Birds|journal=Circulation|volume=21|issue=5|pages=955–967|doi=10.1161/01.cir.21.5.955|year=1960}}
19. ^{{cite journal|author=D’Amico, V. L., Coria, N., Palacios, M. G., Barbosa, A., & Bertellotti, M. |title=Physiological differences between two overlapped breeding Antarctic penguins in a global change perspective|journal=Polar Biology|volume=39|pages=57–64|doi=10.1007/s00300-014-1604-9|year=2016}}
20. ^{{cite journal|author=Actams, N. J. |title= Embryonic metabolism, energy budgets and cost of production of king Aptenodytes patagonicus and gentoo Pygoscelis papua penguin eggs|journal= Comparative Biochemistry and Physiology Part A: Physiology|volume= 101|issue= 3|pages= 497–503|doi=10.1016/0300-9629(92)90501-g|year= 1992}}
21. ^February 2014 observation and photo report by Robert Runyard, translator for INACH (Chilean Antarctic Institute).