The King Penguin is the second largest species of penguin at about
90 cm (3.0 ft) tall and weighing 11 to 16 kg (24 to 35 lb), second
only to the Emperor Penguin. Like all penguin species, it has a streamlined
body to minimise drag while swimming, webbed feet to propel more force
when swimming, and wings that have become stiff, flat flippers. There
is little difference in plumage between the male and female, although
the latter are slightly smaller. The upper parts features of the King
penguin include a silvery-grey back with a blackish-brown head decorated
with ear patches of bright golden-orange. However, rare individuals
have been sighted that have varying degrees of melanism, including
one individual spotted on a National Geographic Society expedition
to South Georgia Island that was completely black. The 12–13
cm (4¾–5 in) black bill is long and slender, and curved
downwards like a banana peel. The lower mandible bears a striking
pink or orange-coloured mandibular plate. An immature bird will have
yellow, rather than orange-tinged markings, and grey tips to its black
brown feathers. It moults into adult plumage at after reaching two
years of age.
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 King Penguin is able to breed at three years of age, although
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 (? lb). It is initially soft, but hardens and darkens
to a pale greenish colour. It measures around 10 × 7 cm (3.9
× 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 young chick is brooded in what is called the guard phase, spending
its time balanced on its parents' feet and sheltered by its pouch.
During this time, the parents alternate every 3–7 days, one
incubating while the other forages. This period lasts for 30–40
days before the chicks form crèches, a group of many chicks
together. A penguin can leave its chick at a crèche while it
fishes as a few adult penguins stay behind to look after them. Other
varieties 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 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. Slender escolar
is also consumed. Cephalopods consumed include the hooked squid and
the Sevenstar Flying.
The King Penguin's predators include birds and aquatic mammals; Skua
species take small chicks and eggs, while the Snowy Sheathbill scavenges
for dead chicks and unattended eggs. The Leopard Seal takes adult
birds at sea. Orcas may also hunt king penguins.