King Penguin

About the king penguin

The king penguin is the second-largest species of penguin, smaller than but similar in appearance to the emperor penguin. It stands 70 to 100 cm (28 to 39 in) tall and weighs from 9.3 to 18 kg (21 to 40 lb), with large individuals reaching around 20 kg (44 lb) before molting; overall, it is roughly 25 percent shorter and about a third lighter than the emperor penguin. Males and females look alike, though they can be told apart by their calls, and males run slightly larger. A study on Marion Island found adult males averaged 12.4 kg (27 lb) and females 11.1 kg (24 lb).

At a glance, the king penguin resembles the emperor penguin, with a broad cheek patch set against dark surrounding feathers and yellow-orange plumage at the top of the chest. The two are distinguishable up close: the king penguin's cheek patch is a solid bright orange, versus yellow and white in the emperor, and its upper chest leans more orange than yellow. Markings along the lower mandible tend toward pink in the emperor and orange in the king. The king penguin also has a longer, straighter bill, larger flippers, and a sleeker body than the emperor, and the two species do not typically share the same range in the wild. Chicks are covered in heavy dark brown down and have a long bill, quite different from the grey, black-and-white-masked chicks of the emperor penguin. Once juveniles molt out of their brown down, they resemble adults but are less colorful. The king penguin's back is a grizzled, sooty grey rather than black, which along with its larger size and taller frame distinguishes it from other penguin species it often breeds alongside.

Behavior and diet

King penguins are strong divers, regularly diving during daylight hours to depths of 100 to 300 m (330 to 980 ft) and remaining submerged for around five minutes at a time, with dives at night generally shallower than 30 m (98 ft). A dive of 235 m was recorded in 1982, and the current recorded maximum reaches 343 m, with a maximum submersion time of 552 seconds. Most dives, around 88 percent in one study, are flat-bottomed: the bird descends to a set depth, hunts there for roughly half the dive, then returns to the surface. The remaining dives follow a V-shaped or "spike" pattern. Observations at the Crozet Islands found most foraging happens within about 30 km (19 mi) of the breeding colony, and the bird swims at an average speed of 6.5 to 10 km/h (4.0 to 6.2 mph), slower on shallow dives and faster on deep ones. On land, the king penguin walks with a wobbling gait or "toboggans," sliding on its belly while pushing with its feet and flippers. Like all penguins, it cannot fly.

The diet consists of small fish, squid, and krill, with fish making up roughly 80 percent of intake except in July and August, when they drop to about 30 percent. Lanternfish are the primary prey. Predators include giant petrels, which take chicks, eggs, and occasionally sick or injured adults; skuas, which take eggs and small chicks; the snowy sheathbill and kelp gull, which scavenge unattended eggs and dead chicks; the leopard seal, which takes adults and fledglings at sea; and orcas, which hunt adult king penguins.

Breeding is unusually drawn out, taking 14 to 16 months from laying to fledging, and, in a triennial pattern recorded at South Georgia, pairs are typically successful only one year in two or two years in three. King penguins are serially monogamous, keeping one mate per season, though fidelity between years is under 30 percent. Breeding starts around three years of age for a small minority, with most birds first breeding at 5 to 6 years old. The female lays a single pear-shaped white egg weighing 300 g (0.66 lb), which both parents incubate in shifts of 6 to 18 days, balancing it on their feet inside a brood pouch, for about 55 days. After hatching, chicks spend a guard phase of 30 to 40 days sheltered in a parent's brood pouch before joining a group of other chicks called a crèche, watched over by a few adults while most parents forage. Because of their large size, chicks need 14 to 16 months before they are ready to go to sea, a far longer rearing period than smaller penguin species need.

Range and habitat

King penguins breed on subantarctic islands between 45 and 55 degrees south, near the northern edge of Antarctica, including South Georgia, the Falkland Islands, the Argentinian part of Tierra del Fuego, and other temperate islands in the region, as well as Macquarie Island in the Southern Ocean. The largest breeding colonies are on the Crozet Islands, with around 455,000 pairs, followed by the Prince Edward Islands with 228,000 pairs, the Kerguelen Islands with 240,000 to 280,000, and South Georgia with over 100,000. Macquarie Island holds around 70,000 pairs. Vagrant birds have turned up on the Antarctic Peninsula and as far afield as South Africa, Australia, and New Zealand. In the early 1920s, whalers based on South Georgia and the Falklands, which had no trees for firewood, nearly wiped out local king penguin populations by burning penguins for fuel and using their oil, meat, and feathers; the species is now fully protected.

Conservation status

The king penguin is listed as Least Concern on the IUCN Red List, in a 2020 assessment by BirdLife International. The total population is estimated at 2.23 million breeding pairs and is increasing. That is a recovery: by the early 1920s, whalers on South Georgia and the Falklands had nearly wiped the birds out there, burning them as fuel to render whale blubber.

The overall trend masks serious local losses. One of the largest known colonies, on Île aux Cochons in the Crozet Islands, fell from about half a million breeding pairs in the 1980s to roughly 60,000 pairs by 2017, a crash thought to be linked to climate-driven shifts in its food supply.

Climate change is the main long-term threat. King penguins get about 80 percent of their food at the Antarctic Convergence, and ocean warming could push that front farther from the breeding islands. Projections suggest that 70 percent of the population could disappear within 80 years and that nearly half could lose its breeding grounds by 2100.