Antarctic Gentoo Penguin

Pygoscelis papua ellsworthi

 Gentoo penguin (Pygoscelis papua), more rarely called red-billed penguin, is a species of penguin in the genus of long-tailed penguins (Pygoscelis) and is most closely related to Adélie penguin (P. adeliae) and chinstrap penguin (P. antarctica). The first scientific description under the name Aptenodytes papua was made in 1781 by Johann Reinhold Forster based on a specimen killed on the Falkland Islands and then brought to London.

Gentoo penguins are the fastest swimmers among the penguins, they reach up to 27 km / h (according to other sources up to 36 km / h) but only swim up to 6 km / h on average. The gentoo penguin is also considered to be the shyest known species of penguin. It gets its name from the donkey-like screams that warn of egg thieves and that can also be heard during the mating season. Two subspecies are recognized, which differ only in their height. The Gentoo Penguin is classified as near threatened by the IUCN. It has an average life expectancy of 15 years

Gentoo penguins reach a body length between 75 and 90 centimeters. They are medium-sized penguins, only the emperor and king penguins are larger. The weight of gentoo penguins varies depending on the season and is between 4.7 and 7.4 kilograms. They reach their highest weight shortly before moulting. There is no pronounced sexual dimorphism, but the females tend to be somewhat smaller. The plumage shows no seasonal differences, juvenile birds can be distinguished from adult birds by their plumage up to an age of one year. The gentleman's most striking feature is the often triangular white spot above the eye.

The throat and head are black except for the white spot above the eye. The spot usually extends to the top of the head and merges into the white eye ring at the lower end. Individual white feathers can also be found on the head and neck. The upper body is otherwise black-blue and appears brownish shortly before moulting when the plumage is very worn. The underside of the body is white and sharply set off from the black throat. The wings, which have been transformed into fins, are white on the underside with a black spot at the end. The beak is orange-red on the sides. The surface of the upper beak and the tip of the beak are black. The iris is brown. The feet are pale whitish-pink to red.

Fledglings are similar to adult birds, but are smaller and have a dull colored bill. Individual individuals are spotted gray on the throat and chin. Birds in which the white spot on the head does not reach the white eye ring are all young birds. However, there are individual individuals in which this characteristic is already present in the juvenile plumage.

There is no possibility of confusion with other penguin species due to the conspicuous white spot on the face and the reddish beak.

Gentoo penguins are circumpolar and breed on sub-Antarctic islands and the Antarctic Peninsula. Basically, they avoid the pack ice zone. Their range outside of the breeding season has not been carefully investigated. It is generally assumed that adult gentoo penguins stay in the vicinity of their breeding colonies all year round. The marine distribution area extends from the Southern Ocean and South Atlantic to the South Indian Ocean.

However, wanderers also reach the South American coast and are observed up to 43 ° S in Argentina. Random visitors occasionally also reach the coast of Australia and New Zealand.

The main colonies are in the Falkland Islands, where about 36% of the global population breed. There are other large breeding colonies on South Georgia and the Kerguelen. Smaller colonies breed on Macquarie Island, Heard and McDonald Islands, and the Antarctic Peninsula.

The subspecies Pygoscelis papua ellsworthii, which is slightly smaller than the nominate form, breeds on the Antarctic Peninsula with around 20,000 pairs, the southern Shetland Islands with around 17,200 pairs and, to a lesser extent, on the Southern Orkney Islands.

The population is estimated by the IUCN at 520,000 sexually mature birds and thus classified by the IUCN as low risk because some of the most important populations are declining. This is true even though other populations have actually increased. Where the populations have increased, the cause is considered to be reduced food competition with whales, whose populations have decreased significantly in the course of the 20th century.

In the 19th century gentoo penguin populations had declined, in some cases drastically, because the eggs were collected for human consumption and adult penguins were slaughtered to extract oil from their fat layer. This practice was still in use in the 1910s: there is evidence that the crew of a single schooner killed over 70,000 specimens annually in the Falkland Islands in order to extract oil from them. The falls in the Falkland Islands are believed to be still related to the practice of collecting eggs. Gentoo penguins are also sensitive to human disturbance. For example, stocks on the Kerguelen have declined significantly after this island was permanently settled.

Gentoo penguins feed primarily on small fish, octopus and krill. In the more northern colonies, fish dominates the diet. Fish is also the main food in the final phase of rearing youngsters and during the winter months. Gentoo penguins dive up to 212 meters, but most dives are no deeper than 110 meters. The diving depth is influenced by the food available; for numerous breeding colonies it has been proven that a large proportion of the birds do not dive more than 20 meters deep. Usually they look for food for six to ten hours.

On King George Island, 50% of the adult birds breeding there leave the breeding colony between 5 and 7 a.m. and return to the colony between 9 a.m. and 1 p.m. to relieve their partner. These then look for food in the sea and return to the breeding colony around 5 p.m. In contrast to this, in some breeding colonies some of the breeding birds remain at sea during the night. Breeding birds rarely move further than forty kilometers from their breeding colony. Gentoo penguins have also been found searching for food 105 kilometers from the breeding colony.