The king penguin (Aptenodytes patagonicus) is the second largest species of penguin, smaller than but somewhat similar in appearance to the emperor penguin.
King penguins mainly eat lanternfish, squid, and krill. On foraging trips, king penguins repeatedly dive to over , and have been recorded at depths greater than . Predators of the king penguin include giant petrels, skuas, the snowy sheathbill, the leopard seal, and the orca.
The king penguin breeds on the subantarctic islands at the northern reaches of Antarctica, South Georgia, southern Argentina, and other temperate islands of the region. It also lives on Macquarie Island in the Southern Ocean and the Falkland Islands.
This bird was exploited commercially in the past for its blubber, oil, meat, and feathers. Today it is fully protected.
Taxonomy In 1778, the English illustrator John Frederick Miller included a hand-coloured engraving of the king penguin in his Icones animalium et plantarum. He coined the binomial name Aptenodytes patagonica and specified the type locality as the Mari antarctico, the Antarctic Ocean. The work was issued in 10 parts with 6 plates in each part. See: The locality was restricted to South Georgia by Gregory Mathews in 1911.
Purported subspecies The International Ornithologists' Union considers the species monotypic, with no subspecies recognised. However, some taxonomic authorities accept two subspecies, A. p. patagonicus and A. p. halli; in this system, A. p. patagonicus is found in the South Atlantic, and A. p. halli in the South Indian Ocean (on the Kerguelen Islands, Crozet Islands, Prince Edward Islands, and Heard Island and McDonald Islands) and on Macquarie Island.
Appearance
The king penguin stands at tall and weighs from .McGonigal, D., L. Woodworth. (2001). Antarctica and the Arctic: The Complete Encyclopedia. Ontario: Firefly Books. Large individuals can weigh up to around before molting. Although female and male king penguins look alike, they can be separated by their calls. Males are also slightly larger than females. The mean body mass of adults from Marion Island was for 70 males and for 71 females. Another study from Marion Island found that the mean mass of 33 adults feeding chicks was . The king penguin is approximately 25% shorter and weighs around a third less than the emperor penguin.Dunning, John B. Jr. (ed.) (2008). CRC Handbook of Avian Body Masses, 2nd Ed. CRC Press. .
At first glance, the king penguin appears similar to the larger, closely related emperor penguin, with a broad cheek patch contrasting with surrounding dark feathers and yellow-orange plumage at the top of the chest. However, the cheek patch of the adult king penguin is a solid bright orange whereas that of the emperor penguin is yellow and white, and the upper chest tends to be more orange and less yellowish in the king species. Both have colourful markings along the side of their lower mandible, but these tend towards pink in emperor penguin and orange in king penguin.
Emperor and king penguins typically do not inhabit the same areas in the wild, with the possible exception of vagrants at sea, but the two can be distinguished from one another by the king's longer, straighter bill, larger flippers, and noticeably sleeker body. King penguin chicks with their long bill and heavy dark brown down, are completely different in appearance to the mostly grey emperor penguin chicks with their black and white mask. Once moulted out of their brown downy plumage, juvenile king penguins resemble the adults, but are somewhat less colourful.
The king penguin often breeds on the same large circumpolar islands as other penguin species, but it is easily distinguished from other species by its much larger size and taller frame, colourful markings, and grizzled sooty-greyish rather than blackish back.
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 (Argentinian part), 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 the Crozet Islands, 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 in the South Georgia archipelago.
By the early 1920s, the king penguin population in South Georgia and the Falklands was nearly wiped out by whalers based on these islands. Constant fires were required to boil whale blubber for extraction of the oil. As the Falklands and South Georgia had no trees to use for firewood, the whalers burned millions of oily, blubber-rich penguins as fuel. The whalers also used penguin oil for lamps, heating and cooking, in addition to eating the birds and their eggs. Macquarie Island currently has around 70,000 pairs. The non-breeding range is unknown; many vagrant birds have been seen on the Antarctic peninsula as well as in South Africa, Australia, and New Zealand.
One of the largest known king penguin colonies, on Île aux Cochons in the Crozet Islands, experienced a massive drop in its population over the last few decades, from about half a million breeding pairs in the 1980s to about 60,000 breeding pairs in 2017. The cause of this decline may be changes in the ecosystem related to climate change as their primary source of food is moving farther away from places where the penguins can breed. This may result in population declines and shifts in the locations of the king penguin breeding grounds.
The Nature Protection Society released several king penguins at Gjesvær in Finnmark and Røst in Lofoten in northern Norway in August 1936. Penguins were seen in the area several times during the 1940s; there were a few unconfirmed sightings of penguins in the area during the early 1950s, but none have been officially recorded since 1949.
Ecology and behaviour
American zoologist Gerry Kooyman revolutionised 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 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 was recorded at the Crozet Islands. The king penguin dives during daylight hours to depths of , spending around five minutes submerged, and to less than at night.Williams, p. 147
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 remaining 12% of dives have a V-shaped or "spike" pattern, in which the bird dives at an angle through the water column, reaches a certain depth, and then returns to the surface. In contrast, other penguins dive in this latter foraging pattern.Williams, pp. 87–88 Observations at Crozet Islands revealed most king penguins were seen within of the colony. Using the average swimming speed, Kooyman estimated the distance travelled to foraging areas at .
The king penguin's average swimming speed is . On shallower dives under , it averages descending and ascending, while on deeper dives over deep, it averages 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.Williams, p. 3
King penguins have been shown to detect airborne odors from conspecific feathers and feces, indicating that they can use smell to perceive cues associated with their colonies, although the specific behavioural role of this ability remains unclear.
Food
King penguins eat various species of small fish, squid, and krill. Fish constitute roughly 80% of their diet, except in the winter months of July and August, when they make up only around 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 are also consumed. Cephalopods consumed include those of the genus Moroteuthis, the hooked squid (Moroteuthopsis longimana), the sevenstar flying squid (Martialia hyadesii), young Gonatus antarcticus, and Onychoteuthis species.
Predators The king penguin's predators include other seabirds and aquatic mammals:
Giant petrels take many chicks of all sizes and some eggs. They will also occasionally kill adult king penguins, but very likely mostly sick or injured birds. Giant petrels also scavenge adult king penguins and chicks which have died from other causes. Skua species (Stercorarius spp.) take eggs and smaller chicks. Some studies may have overstated the effect skua predation has on king penguin colonies, but large numbers of chicks and eggs are taken in areas where skuas nest close to penguin colonies.Young, E. (2005). Skua and penguin: predator and prey. Cambridge University Press. The snowy sheathbill (Chionis alba) and kelp gull (Larus dominicanus) scavenge for unattended eggs and dead chicks.Williams, p. 40 The leopard seal (Hydrurga leptonyx) takes adult birds and fledglings at sea. Orcas also hunt king penguins. Male and especially pre-adult male Antarctic fur seals on Marion Island have also been observed chasing, killing, and eating king penguins on the beach.
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 5–6 years.Williams, p. 151 King penguins are serially monogamous. They have only one mate each year, and stay faithful to that mate. However, fidelity between years is less than 30%.Williams, p. 54 The unusually long breeding cycle probably contributes to this low rate.Williams, p. 152
The king penguin has a prolonged breeding cycle, taking around 14–16 months from laying to offspring fledging.Williams, p. 148 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 in South Georgia. The reproductive cycle begins between September and November, as birds return to colonies for a prenuptial moult. Those that were unsuccessful in breeding the previous season will usually arrive earlier. They then return to the sea for around three weeks before coming ashore in November or December.Williams, p. 149
The female penguin lays one pyriform (pear-shaped) white egg weighing .Williams, p. 150 It is initially soft but hardens and darkens to a pale greenish colour. It measures around . The egg is incubated for around 55 days with both birds sharing incubation in shifts of 6–18 days each. Like the closely related emperor penguin, the king penguin balances the egg on its feet and incubates it in a brood pouch.