The King Penguin (Aptenodytes patagonicus) is the second largest species of penguin at about 11 to 16 kg (24 to 35 lb), second only to the Emperor Penguin. There are two subspecies—A. p. patagonicus and A. p. halli; patagonicus is found in the South Atlantic and halli elsewhere.
King Penguins eat small fish, mainly lanternfish, and squid and rely less than most Southern Ocean predators on krill and other crustaceans. On foraging trips they repeatedly dive to over 100 metres (330 ft), and have been recorded at depths greater than 300 metres (980 ft).
King Penguins breed on the subantarctic islands at the northern reaches of Antarctica, South Georgia, and other temperate islands of the region. The total population is estimated to be 2.23 million pairs and is increasing.
Distribution and habitat 
King Penguins breed on subantarctic islands between 45 and 55°S, at the northern reaches of Antarctica, as well as Tierra del Fuego, the Falkland Islands, and other temperate islands of the region. The total population is estimated to be 2.23 million pairs and is increasing. The largest breeding populations are on Crozet Island, with around 455,000 pairs, 228,000 pairs on the Prince Edward Islands, 240,000–280,000 on the Kerguelen Islands and over 100,000 on the South Georgia Islands. Macquarie Island has around 70,000 pairs. The non-breeding range is poorly known though presumably the subantarctic waters of the southern Indian, South Atlantic and Asian part of the Southern Ocean. Vagrant birds have been recorded from the Antarctic peninsula as well as South Africa, Australia and New Zealand.
The Nature Protection Society released King Penguins in Gjesvær in Finnmark, and Røst in Lofoten in northern Norway in August 1936. Birds were reported in the area several times in the 1940s though none have been seen since 1949.
American zoologist Gerry Kooyman revolutionized the study of penguin foraging behaviour in 1971 when he published his results from attaching automatic dive-recording devices to Emperor Penguins, and recording a dive of 235 metres (771 ft) by a King Penguin in 1982. The current maximum dive recorded is 343 metres in the Falkland Islands region, and a maximum time submerged of 552 seconds recorded at the Crozet Islands. The King Penguin dives to depths of 100–300 meters (350–1000 feet), spending around 5 minutes submerged, during daylight hours, and less than 30 metres (98 ft) at night.
The majority (around 88% in one study) of dives undertaken by King Penguins are flat-bottomed; that is, the penguin dives to a certain depth and remains there for a period of time hunting (roughly 50% of total dive time) before returning to the surface. They have been described as U-shaped or W-shaped, relating to the course of the dive. The bird dives in a V-shaped or 'spike' pattern in the remaining 12% of dives; that is the bird dives at an angle through the water column, reaches a certain depth and then returns to the surface. Other penguins dive in this latter foraging pattern in contrast. Observations at Crozet Islands revealed most King Penguins were seen within 30 km (19 mi) of the colony. Using the average swimming speed, Kooyman estimated the distance travelled to foraging areas at 28 km (17 mi).
Its average swimming speed is 6.5–10 km/h (4–6 mph). On shallower dives under 60 m (200 ft), it averages 2 km/h (1.2 mph) descending and ascending, while on deeper dives over 150 m (490 ft) deep, it averages 5 km/h (3.1 mph) in both directions. King Penguins also porpoise, a swimming technique used to breathe while maintaining speed. On land, the King Penguin alternates between walking with a wobbling gait and tobogganing—sliding over the ice on its belly, propelled by its feet and wing-like flippers. Like all penguins, it is flightless.
King Penguins eat small fish, and squid and rely less than most Southern Ocean predators on krill and other crustaceans. Fish constitute 80–100% of the diet, except in winter months of July and August, when they make up only 30%. Lanternfish are the main fish taken, principally the species Electrona carlsbergi and Krefftichthys anderssoni, as well as Protomyctophum tenisoni. Slender escolar (Paradiplospinus gracilis) of the Gempylidae, and Champsocephalus gunneri, is also consumed. Cephalopods consumed include those of the genus Moroteuthis, the Nopehooked squid species Kondakovia longimana, the Sevenstar Flying Squid (Martialia hyadesii), young Gonatus antarcticus and Onychoteuthis species.
The King Penguin's predators include birds and aquatic mammals:
- Skua species (Stercorarius spp.) take small chicks and eggs.
- The Snowy Sheathbill (Chionis alba) scavenges for dead chicks and unattended eggs.
- The Leopard Seal (Hydrurga leptonyx) takes adult birds at sea.
- Orcas may also hunt King Penguins.
- Antarctic Fur Seals on Marion Island have also been seen chasing King Penguins on the beach, killing and eating them. It seems that especially males, and particularly sub-adults males, are involved.
Courtship and breeding 
The King Penguin is able to breed at three years of age, although only a very small minority (5% recorded at Crozet Islands) actually do then; the average age of first breeding is around 6 years. King Penguins are serially monogamous. They have only one mate each year, and stay faithful to that mate. However, fidelity between years is only about 29%. The long breeding cycle may contribute to this low rate.
The King Penguin has an unusually prolonged breeding cycle, taking some 14–16 months from laying to offspring fledging. Although pairs will attempt to breed annually, they are generally only successful one year in two, or two years in three in a triennial pattern on South Georgia. The reproductive cycle begins in September to November, as birds return to colonies for a prenuptial moult. Those that were unsuccessful in breeding the previous season will often arrive earlier. They then return to the sea for three weeks before coming ashore in November or December. The female penguin lays one pyriform (pear-shaped) white egg weighing 300 g (⅔ lb). It is initially soft, but hardens and darkens to a pale greenish colour. It measures around 10 cm × 7 cm (3.9 in × 2.8 in). The egg is incubated for around 55 days with both birds sharing incubation in shifts of 6–18 days each. Hatching may take up to 2–3 days to complete, and chicks are born semi-altricial and nidicolous. In other words, they have only a thin covering of down and are entirely dependent on their parents for food and warmth. The guard phase starts with the birth of the chick. The young chick spends its time balanced on its parents' feet, sheltered by a pouch formed from the abdominal skin of the latter. During this time, the parents alternate every 3–7 days, one guarding the chick while the other forages. The guard phase lasts for 30–40 days. By then the chick has grown much bigger, can keep itself warm and protect itself against most predators. It becomes more curious and starts to explore its surroundings. It ends up forming a group with other chicks, a so-called crèche. Crèches are guarded by only a few adult birds; most parents can leave their chick to forage for themselves and their chick. Other species of penguins also practice this method of communal care for offspring.
By April the chicks are almost fully grown, but lose weight by fasting over the winter months, gaining it again during spring in September. Fledging then takes place in late spring/early summer.
King Penguins form huge breeding colonies; for example, the colony on South Georgia Island at Salisbury Plain holds over 100,000 breeding pairs and the one at St. Andrew's Bay over 100,000 birds. Because of the long breeding cycle, colonies are continuously occupied.
The King Penguin feeds its chicks by eating a fish, digesting it slightly and regurgitating the food into the chick's mouth.
Because of their large size, King Penguin chicks take 14–16 months before they are ready to go to sea. This is markedly different from smaller penguins, who rear their chicks through a single summer when food is plentiful. King Penguins time their mating so the chicks will develop over the harshest season for fishing. In this way, by the time the young penguins are finally mature enough to leave their parents, it is summer when food is plentiful and conditions are more favorable for the young to survive alone.
Relationship with humans 
Considered a flagship species, 176 individuals were counted in captivity in North American Zoos and Aquaria in 1999. The species has been bred in captivity at SeaWorld San Diego. The species is exhibited at SeaWorld Orlando, Indianapolis Zoo, Detroit Zoo, Saint Louis Zoo, Newport Aquarium in Newport, Kentucky, Edinburgh Zoo in Scotland, Berlin Zoological Garden in Germany, Zurich Zoo, in the Netherlands Diergaarde Blijdorp, in Switzerland, 63 Seaworld in Seoul, South Korea, Melbourne Aquarium in Australia, Mar del Plata Museum of the Sea in Argentina, Loro Parque in Spain and Ski Dubai in United Arab Emirates, and Calgary Zoo in Canada.
The King Penguin is the emblem of Edinburgh Zoo.
Roger Tory Peterson's ornithological nickname was "King Penguin".
Notable King Penguins 
- Sir Nils Olav, mascot and Colonel in Chief of the Royal Norwegian Guard
- Misha, a central character and metaphor in two novels by Ukrainian writer Andrey Kurkov
- The King Penguin is also the species of penguin represented by the popular character Pondus, an image found on various paraphernalia in many retail stores throughout Canada. Pondus originates in Danish children's books written and photographed by Ivar Myrhøj and published in 1997 by Lademann publisher in the late 1960s. These penguins appeared in the production of Batman Returns.
- Opus the Penguin, a fictional character in the comic strips Bloom County, Outland, and Opus, is a King Penguin and the most famous character of the comic strips.
- Rex,a fictional penguin that is in a presentation (along with the other fictional penguin, Rocky) at the Newport Aquarium.
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