Gentoo penguin | |
---|---|
At Brown Bluff, Tabarin Peninsula | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Sphenisciformes |
Family: | Spheniscidae |
Genus: | Pygoscelis |
Species: | P. papua |
Binomial name | |
Pygoscelis papua (Forster, 1781) | |
Distribution of the gentoo penguin |
The gentoo penguin ( /ˈdʒɛntuː/ JEN-too) (Pygoscelis papua) is a penguin species (or possibly a species complex) 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 type locality in the Falkland Islands. The species calls in a variety of ways, but the most frequently heard is a loud trumpeting, which the bird emits with its head thrown back. [2]
The application of "gentoo" to the penguin is unclear. Gentoo was an Anglo-Indian term to distinguish Hindus from Muslims. [3] The English term may have originated from the Portuguese gentio ("pagan, gentile"). Some speculate that the white patch on the bird's head was thought to resemble a turban. [4]
It may also be a variation of another name for this bird, "Johnny penguin", with Johnny being the Spanish counterpart of Juanito and sounding vaguely like gentoo. [5] [6] [7] The Johnny rook, a predator, is likely named after the Johnny penguin. [8]
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 being over 6000 km to the south (on Macquarie Island). [4] No penguins are found in New Guinea. [9] 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. [10]
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 (Mya), about 2 million years after the ancestors of the genus Aptenodytes . In turn, the Adélie penguins split off from the other members of the genus around 19 Mya and the chinstrap and gentoo finally diverged around 14 Mya. [11]
There are 4 subspecies recognized by the International Ornithological Congress: [12]
Image | Subspecies | Distribution |
---|---|---|
P. p. taeniata (eastern gentoo penguin) (Peale, 1849) | Crozet Islands, Prince Edward Islands, Kerguelen Islands, Heard Island, and Macquarie Island | |
P. p. papua (northern gentoo penguin) (Forster, 1781) | Falkland Islands, Martillo Island in the Beagle Channel, and Isla de los Estados (Argentina) | |
P. p. ellsworthi (southern gentoo penguin) Murphy, 1947 | the Antarctic Peninsula, the South Orkney Islands, South Shetland Islands and South Sandwich Islands | |
P. p. poncetii (South Georgia gentoo penguin) Tyler, Bonfitto, Clucas, Reddy & Younger, 2020 | South Georgia Island | |
Although the population on the Kerguelen Islands is tentatively included in taeniata, it may also be a distinct subspecies. [13]
Before 2021, only two subspecies of the gentoo penguin have been recognised: P. p. papua (subantarctic gentoo) and the smaller P. p. ellsworthi (Antarctic gentoo). [14] [15] However, a 2020 study suggested that the gentoo penguin be split into a species complex of four morphologically similar but separate species: the northern gentoo penguin (P. papua sensu stricto), the southern gentoo penguin (P. ellsworthi), the eastern gentoo penguin (P. taeniata) and the newly described South Georgia gentoo penguin (P. poncetii). [16] [17] The International Ornithological Congress incorporated the results of this study in 2021, but relegated the newly recognized or newly described species to being subspecies of P. papua. [13]
The gentoo penguin is easily recognised 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". [18]
Gentoo penguins can reach a length of 70 to 90 cm (28 to 35 in), [19] [20] making them the third-largest species of penguin after the emperor penguin and the king penguin. Males have a maximum weight around 8.5 kg (19 lb) just before moulting and a minimum weight of about 4.9 kg (11 lb) just before mating. For females, the maximum weight is 8.2 kg (18 lb) just before moulting, but their weight drops to as little as 4.5 kg (9.9 lb) when guarding the chicks in the nest. [21] Birds from the north are on average 700 g (1.5 lb) heavier and 10 cm (3.9 in) longer than the southern birds. Southern gentoo penguins reach 75–80 cm (30–31 in) in length. [22] They are the fastest underwater swimmers of all penguins, reaching speeds up to 36 km/h (22 mph). [23] Gentoos are well adapted to extremely cold and harsh climates.
The breeding colonies of gentoo penguins are located on ice-free surfaces. Settlements can be located directly on the shoreline or 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. In colonies farther inland, where the penguins nest in grassy areas, they shift location slightly yearly because the grass becomes trampled over time.
Gentoos breed on many subantarctic 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, Crozet 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. [24] Nests are usually made from a roughly circular pile of stones and can be quite large, 20 cm (7.9 in) high and 25 cm (9.8 in) 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 favours of a female by offering her a choice stone.
Two eggs are laid, both weighing around 130 g (4.6 oz). 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 moult into subadult plumage and go out to sea at around 80 to 100 days.
Gentoos mainly live on fish, crustaceans such as krill and shrimp, and cephalopods. [25] In February and March, crustaceans make up about 10% of the diet, but from March to June, it is about 75%. From June to October, grey rockcod (Lepidonotothen squamifrons) make up 90% of their diet. [25] Cephalopods make up only 10% of the diet throughout the year.
Gentoos 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 ). Other prey include Channichthys rhinoceratus and octopuses. [25]
The gentoos' diet is high in salt, as they eat organisms with relatively the same salinity as seawater, which 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. [26]
Gentoo penguins do not store as much fat as Adélie penguins, their closest relative; gentoos require less energy investment when hunting because the net gain of energy after hunting is greater in gentoos than Adélies. [27] As embryos, gentoos require a lot of energy to develop. Oxygen consumption is high for a developing gentoo embryo. As the embryo grows and requires more oxygen, consumption increases exponentially until the gentoo chick hatches. By then, the chick is consuming around 1800 ml O2 per day. [28]
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 kill injured and sick adult gentoos. Various other seabirds, such as the kelp gull and snowy sheathbill, also snatch chicks and eggs. Skuas on King George Island have been observed attacking and injuring adult gentoo penguins in apparent territorial disputes. [29]
The population of Pygoscelis papua in the maritime Antarctic is rapidly increasing. Due to regional climate changes, they colonise previously inaccessible territories southwards.As of 2019 [update] , the IUCN Red List lists the gentoo as least concerned with a stable population trend, although rapid declines in some key areas are believed to be driving a moderate overall decline in the species population. Examples include Bird Island, South Georgia, where the population has fallen by two-thirds over 25 years. [1] Many threats to this species, including pollution, hunting, fishing and human recreational activities continue to affect them. [30] [31]
The Linux distribution Gentoo Linux is named after the gentoo penguin. This is a nod to the fact that the penguin is the fastest swimming penguin, as Gentoo Linux aims to be a high-performance operating system. [32] : 383 The mascot for Linux in general is a penguin.
Penguins are a group of aquatic flightless birds from the family Spheniscidae of the order Sphenisciformes. 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 ocean 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 whole while swimming. A penguin has a spiny tongue and powerful jaws to grip slippery prey.
The Adélie penguin is a species of penguin common along the entire coast of the Antarctic continent, which is the only place where it is found. It is the most widespread penguin species, and, along with the emperor penguin, is the most southerly distributed of all penguins. It is named after Adélie Land, in turn, named for Adèle Dumont d'Urville, who was married to French explorer Jules Dumont d'Urville, who first discovered this penguin in 1840. Adélie penguins obtain their food by both predation and foraging, with a diet of mainly krill and fish.
The sheathbills are a family of birds, Chionidae. Classified in the wader order Charadriiformes, the family consists of one genus, Chionis with two species. They breed on subantarctic islands and the Antarctic Peninsula, and the snowy sheathbill migrates to the Falkland Islands and coastal southern South America in the southern winter; they are the only bird family endemic as breeders to the Antarctic region. They are also the only Antarctic birds without webbed feet.
The emperor penguin is the tallest and heaviest of all living penguin species and is endemic to Antarctica. The male and female are similar in plumage and size, reaching 100 cm (39 in) in length and weighing from 22 to 45 kg. Feathers of the head and back are black and sharply delineated from the white belly, pale-yellow breast and bright-yellow ear patches.
The chinstrap penguin is a species of penguin that inhabits a variety of islands and shores in the Southern Pacific and the Antarctic Oceans. Its name stems from the narrow black band under its head, which makes it appear as if it were wearing a black helmet, making it easy to identify. Other common names include ringed penguin, bearded penguin, and stonecracker penguin, due to its loud, harsh call.
The southern rockhopper penguin is a species of rockhopper penguin, that is sometimes considered distinct from the northern rockhopper penguin. It occurs in subantarctic waters of the western Pacific and Indian Oceans, as well as around the southern coasts of South America.
The king penguin is the second largest species of penguin, smaller, but somewhat similar in appearance to the emperor penguin. There are two subspecies, A. p. patagonicus and A. p. halli; patagonicus is found in the South Atlantic and halli in the South Indian Ocean and at Macquarie Island.
The macaroni penguin is a species of penguin found from the Subantarctic to the Antarctic Peninsula. One of six species of crested penguin, it is very closely related to the royal penguin, and some authorities consider the two to be a single species. It bears a distinctive yellow crest that resembles macaroni, from which its name is derived. Its face and upperparts are black and sharply delineated from the white underparts. Adults weigh on average 5.5 kg (12 lb) and are 70 cm (28 in) in length. The male and female are similar in appearance; the male is slightly larger and stronger with a relatively larger bill. Like all penguins, it is flightless, with a streamlined body and wings stiffened and flattened into flippers for a marine lifestyle.
The yellow-eyed penguin, known also as hoiho, is a species of penguin endemic to New Zealand.
The genus Pygoscelis ("rump-legged") contains three living species of penguins collectively known as "brush-tailed penguins".
The rockhopper penguins are three closely related taxa of crested penguins that have been traditionally treated as a single species and are sometimes split into three species.
The brown skua, also known as the Antarctic skua, subantarctic skua, southern great skua, southern skua, or hākoakoa (Māori), is a large seabird that breeds in the subantarctic and Antarctic zones and moves further north when not breeding. Its taxonomy is highly complex and a matter of dispute, with some splitting it into two or three species: Falkland skua, Tristan skua, and subantarctic skua. To further confuse, it hybridizes with both the south polar and Chilean skuas, and the entire group has been considered to be a subspecies of the great skua, a species otherwise restricted to the Northern Hemisphere.
The southern giant petrel, also known as the Antarctic giant petrel, giant fulmar, stinker, and stinkpot, is a large seabird of the southern oceans. Its distribution overlaps broadly with the similar northern giant petrel, though it overall is centered slightly further south. Adults of the two species can be distinguished by the colour of their bill-tip: greenish in the southern and reddish in the northern.
The striated caracara or Forster's caracara is a Near Threatened bird of prey of the family Falconidae, the falcons and caracaras. It is found in Argentina, Chile, and the Falkland Islands. In the Falklands it is known as the Johnny rook, probably named after the Johnny penguin.
The Antarctic tern is a seabird in the family Laridae. It ranges throughout the southern oceans and is found on small islands around Antarctica as well as on the shores of the mainland. Its diet consists primarily of small fish and crustaceans. It is very similar in appearance to the closely related Arctic tern, but it is stockier, and it is in its breeding plumage in the southern summer, when the Arctic tern has shed old feathers to get its non-breeding plumage. The Antarctic tern does not migrate like the Arctic tern does, but it can still be found on a very large range. This tern species is actually more closely related to the South American tern.
The Southern Indian Ocean Islands tundra is a tundra ecoregion that includes several subantarctic islands in the southern Indian Ocean.
The eastern rockhopper penguin, also known as the tawaki piki toka, is a crested penguin with yellow crest feathers. It is a subspecies of the southern rockhopper penguin found in subantarctic regions and the Indian Ocean. It is one of the smallest crested penguins and has distinctive pink margins around its bill.
Gourdin Island is the largest island (124 ha) in a group of islands and rocks 2 km (1 nmi) north of Prime Head, the northern tip of the Antarctic Peninsula. It was discovered by a French expedition, 1837–40, under Captain Jules Dumont d'Urville, and named by him for Ensign Jean Gourdin of the expedition ship Astrolabe. The island was reidentified and charted by the Falkland Islands Dependencies Survey in 1945–47.
Until the 1930s, the gentoo was generally known in the Falklands as the Johnny penguin.
In the 18th century, English-speaking sealers commonly called [the gentoo] the Johnny penguin. The Spanish translation of this was Juanito, which has degenerated into gentoo.
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".
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 ejected from the colony.
This article incorporates text from the ARKive fact-file "Gentoo penguin" under the Creative Commons Attribution-ShareAlike 3.0 Unported License and the GFDL .