King penguin

Name and taxonomy

The English illustrator John Frederick Miller published a hand-coloured plate of the bird in 1778. He gave it the name Aptenodytes patagonica and set the type locality as the Antarctic Ocean. Gregory Mathews narrowed that locality to South Georgia in 1911. The genus Aptenodytes holds only this bird and the emperor penguin.

The International Ornithologists' Union treats the species as one form, with no subspecies. Other authorities split it in two, one in the South Atlantic and one in the South Indian Ocean. French speakers call the bird manchot royal, Spanish speakers pingüino rey and Portuguese speakers pinguim-rei. The word king in the name probably marks its size beside the smaller penguins of the same islands.

Evolution and relatives

The king penguin sits in the family Spheniscidae, which holds every living penguin. Its closest relative is the emperor penguin, the only other member of the genus. The two look alike at a glance, and both carry an egg on their feet instead of building a nest. The emperor breeds on sea ice in the Antarctic winter, while the king breeds on island beaches.

The king is about a quarter shorter than the emperor and weighs around a third less. Its cheek patch is solid orange, and the emperor's is yellow fading into white. The king has a longer, straighter bill, larger flippers and a sleeker body. Bone studies show the species grows in two phases, split by a winter fast, which appears unique among penguins. That growth pattern probably follows from the long breeding cycle rather than from ancestry.

Appearance

An adult stands 85 to 95 centimetres tall and weighs 9.3 to 17.3 kg, with an average near 11.8 kg. Weight swings through the year, because the bird fasts for weeks on shore. Males average about 12.8 kg and females about 11.5 kg. The head is almost black, with a spoon-shaped orange patch behind each eye. Orange is strongest at the throat, then fades to pale yellow and to a white belly.

The back and flippers are grey and black with a silvery sheen, and a thin black line edges the flanks. The long slender bill carries a coloured stripe on the lower half, from pinkish red to orange-yellow. That stripe reflects ultraviolet light, and researchers think it signals maturity, health or standing. Chicks wear thick dark brown down and look nothing like the adults. Juveniles that have moulted resemble their parents but carry duller colour until about three years old.

Habitat and range

The species breeds on subantarctic island beaches lying between 45 and 55 degrees south. The main colonies lie on the Crozet, Prince Edward, Kerguelen, Heard, Macquarie and South Georgia islands. Birds also breed on the Falkland Islands and on the Argentine part of Tierra del Fuego. No colony has been found south of 60 degrees south, so this is not a bird of the ice shelf.

Colonies sit on flat, sparsely vegetated ground near a beach, because the birds avoid climbing. At sea the species stays around the Antarctic Convergence, where its fish gather. Wanderers reach South Africa, Australia, New Zealand, Brazil and the Antarctic Peninsula. GBIF holds records from 23 countries and territories, most of them from Heard Island and South Georgia. Norway released birds at Gjesvær and Røst in 1936, and the last accepted sighting there was in 1949.

Diet and feeding

Fish make up roughly 80 percent of the diet for most of the year. In July and August that share falls to around 30 percent, and squid takes its place. Lanternfish are the main catch, along with slender escolar and icefish. Squid taken include the hooked squid and the sevenstar flying squid. Krill fills out the rest of the diet.

The bird feeds by day and dives repeatedly to between 100 and 300 metres. It stays under for about five minutes on a working dive. At night it works shallower water, less than 30 metres down. The deepest dive on record reached 343 metres near the Falkland Islands. The longest recorded dive lasted 552 seconds, at the Crozet Islands.

About 88 percent of dives are flat-bottomed, so the bird holds a depth and hunts along it. The remaining dives cut down through the water and come straight back up. Average swimming speed is 6.5 to 10 kilometres per hour. Foraging trips can run 300 to 500 kilometres from the colony and last more than a week.

Behaviour and social life

King penguins live in dense colonies that are occupied all year round. The colony at St Andrews Bay in South Georgia holds over 150,000 pairs. Birds build no nest, but each pair defends about half a square metre of ground. Positions in a colony stay stable for weeks and are spaced at pecking distance. Penguins near the centre are more aggressive and breed more successfully than those at the edge.

On land the bird alternates a wobbling walk with tobogganing on its belly. At sea it porpoises, leaping clear of the surface to breathe without losing speed. Birds huddle together in blizzards to hold their heat. They bathe in the sea before a fishing trip. Like other penguins, this bird cannot fly at all.

Communication and senses

The voice comes from a two-part syrinx, and each half makes its own sound. Among penguins that organ is found only in this genus. A colony is loud, so an adult calls out three to seven syllables at two frequencies to find its chick. The chick appears to pick out the lower frequency, which carries further through the noise. Researchers call this the cocktail-party effect, and a chick learns the call in its first five weeks.

Without nests or landmarks, that call is the only way a parent finds its own young. Males advertise with a trumpeting call and stretch to full height with the bill raised. A pair that forms then bows, shakes, struts and calls face to face. The birds can also smell feathers and droppings of their own species, which may help them locate a colony.

Reproduction and life cycle

The cycle starts between September and November, when adults come ashore to moult. They go back to sea for about three weeks, then land again to court in November or December. The female lays one pear-shaped white egg that weighs 300 grams. The egg measures about 10 centimetres by 7 cm and hardens to a pale green. No nest is built, so the egg rests on the parent's feet under a fold of belly skin.

Incubation lasts around 55 days, and the pair swap shifts of 6 to 18 days. Hatching can take two or three days, and the chick emerges with only thin down. For 30 to 40 days a parent guards the chick on its feet while the other feeds at sea. The pair change places every three to seven days during that guard phase. Chicks then gather in a crèche watched over by a few adults.

A chick is almost full grown by April, then loses weight through a winter fast. It regains the weight in September and goes to sea in late spring or early summer. The whole cycle takes 14 to 16 months, so a pair cannot raise a chick every year. Most successful pairs breed twice in three years, and fidelity between years is under 30 percent. Birds can breed at three years old, but the average age at first breeding is five or six. One banded wild bird reached at least 27 years, and captive birds live up to 26 years.

Predators and threats

Leopard seals take adults and fledglings in the water. Orcas hunt king penguins at sea, and fur seals kill them on the beach. Giant petrels take chicks of every size and sometimes kill weak adults. Skuas take eggs and small chicks, and sheathbills and kelp gulls scavenge what is left. None of these hunters appears to hold the population down.

Hard ticks and a bird louse both infest king penguins. Heavy tick infestation has killed birds, though the death rate is not known. Commercial fishing for lanternfish is a newer threat, and over 200,000 tonnes were taken near South Georgia by the early 1990s. Ocean warming is pushing the Antarctic Convergence away from the breeding islands.

Population and conservation

The IUCN Red List rates the king penguin as Least Concern. The world population is put at 2.23 million breeding pairs and is rising. The Crozet Islands hold about 455,000 pairs and the Prince Edward Islands about 228,000. Kerguelen holds 240,000 to 280,000 pairs, South Georgia over 100,000 and Macquarie about 70,000. Adult survival has stayed high since the 1970s.

The record is not uniform across the range. The colony on Île aux Cochons fell from about half a million pairs in the 1980s to around 60,000 in 2017. Chile lists the species as Endangered and South Africa as Near Threatened. One projection expects 70 percent of the population to go within 80 years. Colonies in Crozet and Kerguelen sit inside French nature reserves, and Falklands wildlife is protected by a 1999 bill.

Relationship with humans

Whalers on South Georgia and the Falklands nearly destroyed the population by the early 1920s. The islands had no trees, so the crews burned oily penguins as fuel under the blubber pots. They also ate the birds and their eggs and burned the oil in lamps. The species is fully protected today, and the colonies have recovered.

Tourism has replaced hunting as the main contact. In one Falklands study every visitor went to the king penguin colony, and they stayed a mean of 63 minutes. Access to breeding sites is now limited, to keep disease and disturbance out. Zoos keep the bird as a flagship species, and 176 were counted in North American collections in 1999. No one may keep a king penguin privately, and the cold-water diet alone would defeat a keeper.

In culture and myth

The best known king penguin is Nils Olav, mascot of the Norwegian King's Guard at Edinburgh Zoo. The guard adopted the first bird in 1972 and named him after two of its own officers. Successive birds have held the title, rising from lance corporal to colonel-in-chief in 2005. King Harald V knighted Nils Olav in 2008, the first penguin so honoured in the Norwegian army. The third holder became a brigadier in 2016 and a major general in 2023.

Guinness World Records lists him as the highest-ranking penguin, and he carries the title Baron of Bouvet Island. A bronze statue of the bird stands at Edinburgh Zoo and another at the guard's Oslo headquarters. Danish children's books photographed a king penguin named Pondus, who then became a shop character across Canada. Pesto, a very large chick at Sea Life Melbourne, drew wide attention in 2024. The species probably carries no old myth, because no people lived on its islands before sealers arrived.