The gentoo penguin (Pygoscelis papua) is a type of penguin in the genus Pygoscelis. It is closely related to the Adélie penguin (P. adeliae) and the chinstrap penguin (P. antarcticus). The first scientific description of the gentoo penguin was written in 1781 by Johann Reinhold Forster, who identified the penguin based on a specimen found in the Falkland Islands. This penguin makes many different sounds, but the most common is a loud, trumpet-like call, which it produces while tilting its head backward.

Names

The origin of the name "gentoo" for the penguin is not clearly understood. The term "gentoo" was used by people from England and India to describe Hindus and Muslims differently. The English word may come from the Portuguese word "gentio," which means "pagan" or "gentile." Some people think the white area on the bird's head might have looked like a turban.

The name "gentoo" might also be a different version of another name for the bird, "Johnny penguin." "Johnny" could be related to the Spanish nickname "Juanito" and sounds similar to "gentoo." A bird called the "Johnny rook," which is a predator, is likely named after the "Johnny penguin."

The name "papua" is incorrect. Johann Reinhold Forster, a naturalist who traveled around the world with Captain James Cook, wrongly believed the penguin lived in Papua (New Guinea). In reality, the closest gentoo penguins are more than 6,000 km (3,700 miles) south of Papua, on Macquarie Island. No penguins live in New Guinea. Some people believe the mistake started with a claim in 1776 by French naturalist Pierre Sonnerat, who said the king penguin lived in Papua, even though he had never visited the island.

Taxonomy

The gentoo penguin is one of three species in the genus Pygoscelis. DNA studies show that the Pygoscelis genus separated from other penguin groups about 38 million years ago. This happened around 2 million years after the ancestors of the Aptenodytes genus. Later, the Adélie penguins split from other members of the Pygoscelis genus about 19 million years ago. The chinstrap and gentoo penguins finally became separate species about 14 million years ago.

The International Ornithological Congress recognizes four subspecies of the gentoo penguin. The population on the Kerguelen Islands is temporarily grouped with the taeniata subspecies, but it might be a separate subspecies.

Before 2021, scientists identified only two subspecies of the gentoo penguin: P. p. papua (subantarctic gentoo) and the smaller P. p. ellsworthi (Antarctic gentoo). However, a 2020 study suggested that the gentoo penguin should be divided into four closely related 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). In 2021, the International Ornithological Congress used the findings from this study but classified the newly recognized species as subspecies of P. papua.

Description

The gentoo penguin is easily identified by the wide white stripe that looks like a bonnet across the top of its head and its bright orange-red beak. It has pale whitish-pink, webbed feet and a long tail, which is the most noticeable among all penguin species. Chicks have gray backs and white fronts. When walking on land, the gentoo penguin waddles with its tail sticking out behind, moving side to side. This is why its scientific name is Pygoscelis, which means "rump-tailed."

Gentoo penguins can grow to be 70 to 90 cm (28 to 35 inches) long, making them the third-largest penguin species after the emperor penguin and the king penguin. Males weigh up to about 8.5 kg (19 pounds) before moulting and drop to around 4.9 kg (11 pounds) before mating. Females weigh up to 8.2 kg (18 pounds) before moulting but may weigh as little as 4.5 kg (9.9 pounds) when protecting their chicks. Northern gentoo penguins are usually 700 grams (1.5 pounds) heavier and 10 cm (3.9 inches) longer than southern gentoo penguins. Southern gentoo penguins grow to about 75–80 cm (30–31 inches) in length. They are the fastest underwater swimmers among penguins, reaching speeds of up to 36 km/h (22 mph). Gentoo penguins are adapted to survive in very cold and harsh environments.

Breeding

Gentoo penguins build their nests on ice-free areas. Their colonies can be found near the shoreline or far inland. They often choose shallow coastal areas and nest among clumps of grass. For example, in South Georgia, colonies are about 1.2 miles inland. In areas farther inland, where penguins nest in grassy places, they move their nesting spots slightly each year because the grass becomes worn down over time.

Gentoo penguins breed on many islands near the Antarctic. The largest colonies are on the Falkland Islands, South Georgia, the South Sandwich Islands, and the Kerguelen Islands. Smaller colonies are also found on Macquarie Island, Heard Island, Crozet Islands, South Shetland Islands, and the Antarctic Peninsula. Scientists estimate there are more than 600,000 gentoo penguins breeding each year. Their nests are made of a round pile of stones, about 7.9 inches high and 9.8 inches wide. Penguins guard their nests carefully, and fights can happen over ownership of stones. Female penguins value stones highly, and a male may gain a mate’s favor by giving her a special stone.

Gentoo penguins lay two eggs, each weighing about 4.6 ounces. Both parents take turns sitting on the eggs every day. The eggs hatch after 34 to 36 days. The chicks stay in the nest for about 30 days before joining other young penguins in groups called creches. At around 80 to 100 days old, the chicks shed their baby feathers and grow new ones that look different, then swim out to sea.

• Egg, Museum Wiesbaden
• On a nest
• Juveniles on Petermann Island

Diet

Gentoos primarily eat fish, crustaceans such as krill and shrimp, and cephalopods like squid and octopus. In February and March, crustaceans make up about 10% of their food, while from March to June, crustaceans make up about 75%. From June to October, grey rockcod (Lepidonotothen squamifrons) make up 90% of their diet. Cephalopods make up only 10% of their food throughout the year.

Gentoos are opportunistic feeders, and around the Falklands, they eat roughly equal amounts of fish (Patagonotothen sp., Thysanopsetta naresi, Micromesistius australis), squat lobsters (Munida gregaria), and squid (Loligo gahi, Gonatus antarcticus, Moroteuthis ingens). Other prey includes Channichthys rhinoceratus and octopuses.

Physiology

Gentoo penguins eat many sea creatures that have the same salt level as seawater. This high salt intake can cause problems for their bodies, especially for baby gentoos. To help with this, gentoos and other seabirds have a special salt gland above their eyes. This gland removes excess salt from their blood and creates a very salty liquid that flows out of their beaks.

Gentoo penguins store less fat than Adélie penguins, their closest relatives. This is because gentoos gain more energy from hunting than Adélies do. During development, gentoo embryos need a lot of energy. Their oxygen use is very high while they grow. As the embryo develops, oxygen use increases rapidly. By the time the chick hatches, it uses about 1800 milliliters of oxygen each day.

Predators

In the ocean, leopard seals, sea lions, and killer whales hunt gentoo penguins. On land, adult gentoo penguins have no natural enemies. However, birds like skuas and giant petrels often kill baby penguins and take their eggs. Petrels also attack injured or sick adult gentoos. Other seabirds, such as kelp gulls and snowy sheathbills, also steal eggs and harm young penguins. Skuas on King George Island have been seen fighting with adult gentoo penguins over territory.

Conservation status

The number of Pygoscelis papua in the maritime Antarctic is growing quickly. Because of climate changes in the region, these penguins are moving into areas that were previously hard to reach, such as lands farther south. As of 2019, the IUCN Red List classifies the gentoo penguin as least concerned, with population numbers staying the same overall. However, some important areas are experiencing fast population drops, which may be causing a slow decrease in the species’ total numbers. For example, on Bird Island, South Georgia, the population has dropped by two-thirds over 25 years. Threats such as pollution, hunting, fishing, and human recreational activities are still causing problems for this species.

In popular culture

Gentoo Linux is a version of the Linux operating system. It is named after the gentoo penguin. This is because the gentoo penguin is known for being the fastest swimmer among penguins. Gentoo Linux is designed to be a fast and efficient operating system. The mascot for the Linux operating system is a penguin. In the 2011 movie version of Mr. Popper's Penguins, there are six gentoo penguins with the names Captain, Lovey, Loudy, Bitey, Stinky, and Nimrod.

Gallery

• An adult gentoo penguin facing off against a southern giant petrel (Macronectes giganteus) that has killed a chick
• A gentoo penguin swimming in the water
• A group of gentoo penguins on Carcass Island in the Falkland Islands
• A gentoo penguin (left) and a chinstrap penguin (right)
• Saunders Island in the Falkland Islands