Gentoo penguin
Encyclopedia
The Gentoo Penguin Pygoscelis papua, is easily recognized by the wide white stripe extending like a bonnet
across the top of its head and its bright orange-red bill. The gentoo penguin has pale whitish-pink webbed feet and a fairly long tail - the most prominent tail of all penguins. 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’. Adult Gentoos reach a height of 51 to 90 cm (20–36 in), making them the third largest species of penguin after the two giant species, the Emperor Penguin
and the King Penguin
. The Gentoo penguin calls in a variety of ways, but the most frequently heard is a loud trumpeting which is emitted with its head thrown back.
The application of Gentoo to the penguin is unclear, according to the OED, which reports that Gentoo was an Anglo-Indian term, used as early as 1638 to distinguish Hindu
s in India from Muslims, the English term originating in Portuguese gentio (compare "gentile
"); in the twentieth century the term came to be regarded as derogatory.
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 diverging around 14 million years ago.
Two sub-species of this penguin
are recognised: Pygoscelis papua papua and the smaller Pygoscelis papua ellsworthii'
islands. The main colonies are on the Falkland Islands
, South Georgia
and Kerguelen Islands
; smaller populations are found on Macquarie Island
, Heard Islands, South Shetland Islands
and the Antarctic Peninsula
. The total breeding population is estimated to be over 300,000 pairs.
Nests are usually made from a roughly circular pile of stones and can be quite large, 20 cm high and 25 cm in diameter. The stones are jealously guarded and their ownership can be the subject of noisy disputes between individual penguins. 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 nice stone.
Two eggs are laid, both weighing around 500 g. The parents share incubation, changing duty daily. The eggs hatch after 34 to 36 days. The chicks remain in the nests for about 30 days before forming creche
s. The chicks molt into sub-adult plumage and go out to sea at about 80 to 100 days.
s 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), crustaceans (Munida gregaria) and squid
(Loligo gahi, Gonatus antarcticus, Moroteuthis ingens).
s, leopard seal
s, and orca
are all predators of the Gentoo. On land there are no predators of full grown Gentoos. Skua
can steal their eggs; however, some other seabirds have managed to snatch chicks.
Bonnet (headgear)
Bonnets are a variety of headgear for both sexes, which have in common only the absence of a brim. Bonnet derives from the same word in French, where it originally indicated a type of material...
across the top of its head and its bright orange-red bill. The gentoo penguin has pale whitish-pink webbed feet and a fairly long tail - the most prominent tail of all penguins. 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’. Adult Gentoos reach a height of 51 to 90 cm (20–36 in), making them the third largest species of penguin after the two giant species, the Emperor Penguin
Emperor Penguin
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 in height and weighing anywhere from . The dorsal side and head are black and sharply delineated from the white belly,...
and the King Penguin
King Penguin
The King Penguin is the second largest species of penguin at about , second only to the Emperor Penguin. There are two subspecies—A. p. patagonicus and A. p...
. The Gentoo penguin calls in a variety of ways, but the most frequently heard is a loud trumpeting which is emitted with its head thrown back.
The application of Gentoo to the penguin is unclear, according to the OED, which reports that Gentoo was an Anglo-Indian term, used as early as 1638 to distinguish Hindu
Hindu
Hindu refers to an identity associated with the philosophical, religious and cultural systems that are indigenous to the Indian subcontinent. As used in the Constitution of India, the word "Hindu" is also attributed to all persons professing any Indian religion...
s in India from Muslims, the English term originating in Portuguese gentio (compare "gentile
Gentile
The term Gentile refers to non-Israelite peoples or nations in English translations of the Bible....
"); in the twentieth century the term came to be regarded as derogatory.
Taxonomy
The Gentoo Penguin is one of three species in the genus Pygoscelis. Mitochondrial and nuclearCell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
evidence suggests the genus split from other penguins around 38 million years ago, about 2 million years after the ancestors of the genus Aptenodytes
Aptenodytes
The genus Aptenodytes contains two extant species of penguins collectively known as "the great penguins".-Taxonomy:...
. 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 diverging around 14 million years ago.
Two sub-species of this penguin
Penguin
Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers...
are recognised: Pygoscelis papua papua and the smaller Pygoscelis papua ellsworthii'
Description
Males have a maximum weight of about 8.5 kg (19 lb) just before molting, and a minimum weight of about 4.9 kg (10.8 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 (10 lb) when guarding the chicks in the nest. Birds from the north are on average 700 g (1.5 lb) heavier and 10 cm (4 in) taller than southern birds Gentoo penguin reaches 75–80 cm. They are the fastest underwater swimming penguins, reaching speeds of 36 km/h. Gentoo are adapted to very harsh cold climates.Breeding
Gentoos breed on many sub-AntarcticAntarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...
islands. The main colonies are on the Falkland Islands
Falkland Islands
The Falkland Islands are an archipelago in the South Atlantic Ocean, located about from the coast of mainland South America. The archipelago consists of East Falkland, West Falkland and 776 lesser islands. The capital, Stanley, is on East Falkland...
, South Georgia
South Georgia and the South Sandwich Islands
South Georgia and the South Sandwich Islands is a British overseas territory and overseas territory of the European Union in the southern Atlantic Ocean. It is a remote and inhospitable collection of islands, consisting of South Georgia and a chain of smaller islands, known as the South Sandwich...
and Kerguelen Islands
Kerguelen Islands
The Kerguelen Islands , also known as the Desolation Islands, are a group of islands in the southern Indian Ocean constituting the emerged part of the otherwise submerged Kerguelen Plateau. The islands, along with Adélie Land, the Crozet Islands and the Amsterdam and Saint Paul Islands are part of...
; smaller populations are found on Macquarie Island
Macquarie Island
Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between New Zealand and Antarctica, at 54°30S, 158°57E. Politically, it has formed part of the Australian state of Tasmania since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a world heritage...
, Heard Islands, South Shetland Islands
South Shetland Islands
The South Shetland Islands are a group of Antarctic islands, lying about north of the Antarctic Peninsula, with a total area of . By the Antarctic Treaty of 1959, the Islands' sovereignty is neither recognized nor disputed by the signatories and they are free for use by any signatory for...
and the Antarctic Peninsula
Antarctic Peninsula
The Antarctic Peninsula is the northernmost part of the mainland of Antarctica. It extends from a line between Cape Adams and a point on the mainland south of Eklund Islands....
. The total breeding population is estimated to be over 300,000 pairs.
Nests are usually made from a roughly circular pile of stones and can be quite large, 20 cm high and 25 cm in diameter. The stones are jealously guarded and their ownership can be the subject of noisy disputes between individual penguins. 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 nice stone.
Two eggs are laid, both weighing around 500 g. The parents share incubation, changing duty daily. The eggs hatch after 34 to 36 days. The chicks remain in the nests for about 30 days before forming creche
Crèche (zoology)
The Crèche in zoology refers to care of another's offspring, for instance in a colony. This term is used in the study of bird colonies...
s. The chicks molt into sub-adult plumage and go out to sea at about 80 to 100 days.
Diet
Gentoos live mainly on crustaceanCrustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s such as krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
, with fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
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), crustaceans (Munida gregaria) and squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
(Loligo gahi, Gonatus antarcticus, Moroteuthis ingens).
Threats
In the water, sea lionSea Lion
Sea lions are pinnipeds characterized by external ear-flaps, long fore-flippers, the ability to walk on all fours, and short thick hair. Together with the fur seal, they comprise the family Otariidae, or eared seals. There are six extant and one extinct species in five genera...
s, leopard seal
Leopard Seal
The leopard seal , also referred to as the sea leopard, is the second largest species of seal in the Antarctic...
s, and orca
Orca
The killer whale , commonly referred to as the orca, and less commonly as the blackfish, is a toothed whale belonging to the oceanic dolphin family. Killer whales are found in all oceans, from the frigid Arctic and Antarctic regions to tropical seas...
are all predators of the Gentoo. On land there are no predators of full grown Gentoos. Skua
Skua
The skuas are a group of seabirds with about seven species forming the family Stercorariidae and the genus Stercorarius. The three smaller skuas are called jaegers in North America....
can steal their eggs; however, some other seabirds have managed to snatch chicks.
External links
- Gentoo Penguin in the International Union for Conservation of Nature and Natural Resources (IUCN) Homepage
- 70South – more info on the Gentoo penguin
- Gentoo penguins from the International Penguin Conservation Web Site
- www.pinguins.info : information about all species of penguins
- Gentoo Penguin images
- Biodiversity at Ardley Island Small place near King Luis Island, special protected area and colony of Gentoo Penguins.
- Gentoo penguin webcam from the Antarctic – worldwide first webcam with wild penguins; photo quality