The King penguin (Aptenodytes patagonicus) is the second largest species of penguin. This species was exploited commercially in the past for its blubber, oil, meat, and feathers but today, it is fully protected.
At first glance, the King penguin appears very 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, but the two can be distinguished from one another by the King's longer, straighter bill, larger flippers and noticeably sleeker body. The juvenile King penguin with its long bill and heavy dark brown down is completely different in appearance from the mostly grey emperor chick with its black and white mask. Once moulted of its brown juvenile plumage, the King chick resembles the adult, but is somewhat less colourful.
King penguins inhabit rocky islands in the northern reaches of Antarctica, as well as Tierra del Fuego, the Falkland Islands, and other temperate islands of the region.
King penguins are diurnal and social animals, gathering in colonies. Usually, these colonies cover large territories, located in open areas with poor vegetation, since the birds do not tend to climb. In order to forage, King penguins travel long distances (up to 500 km) from their breeding areas. Before feeding, they like to bathe in the ocean. During the daytime, penguins can dive to depths of 100-300 meters (350-1000 feet), remaining there for about 5 minutes before coming to the surface while at night, they usually do not dive deeper than 30 meters (98 ft). When on land, King penguins move either by walking with the characteristic ungainly, wobbling gait or simply sliding over the ice surface on their bellies, pushing themselves with their feet and flippers.
King penguins are carnivores (piscivores). Their diet mainly consists of fish and particularly - lantern fish and they also consume crustaceans such as krill.
The mating behavior of King penguins can be characterized as serial monogamy. During the breeding season, which takes place in November-December, each penguin mates with only one mate. The female lays a single egg. Then, for about 55 days, both the male and the female take part in the incubation of the egg. When the chick hatches out, both parents care for it for about 30-40 days, until the hatchling joins a group of other chicks or crèche, where it finds warmth and protection from predators. Young penguins are independent at 14-16 months old, reaching reproductive maturity at the age of 3-5 years.
One of the threats to this species is human activity within the area of their range, which can cause the introduction of a disease, pest, or predator, which, in turn, can lead to the decline of their population. However, the primary threat to the penguins is global warming: the rise in temperatures has already caused a sharp decline in the breeding success of King penguins. In addition, global warming affects also the species that the penguins consume, slowing down the development of marine organisms.
According to the IUCN Red List resource, the total population size of the King penguin is 1.1 million annual breeding pairs. Currently, this species is classified as Least Concern (LC) on the IUCN Red List, and its numbers today are increasing.
