The king penguin (Aptenodytes patagonicus) is the second largest penguin species after the emperor penguin and breeds in dense colonies on sub-Antarctic islands in the South Atlantic and Indian Oceans. Its life cycle is characterised by a unique breeding period lasting approximately 14–16 months; therefore, pairs can only raise one chick per year. Despite regional pressures from seal hunting and fishing for the fur trade in the early 20th century, the total population of the species is now in the millions and hosts particularly large colonies on the Crozet, South Georgia and Kerguelen Islands. Its population is considered stable on a global scale, and it is therefore classified as ‘Least Concern’ (LC) on the IUCN Red List.
Morphological Characteristics and Systematic Position
Physical Description
The king penguin is the second largest penguin species after the emperor penguin, averaging 85–95 cm in height and 10–16 kg in weight. The back is grey with a bluish tinge, while the belly is bright white; a distinctive orange-yellow patch on the chest and cheek patches extending from the base of the beak to the neck are characteristic features of the species. The beak is long, thin and slightly curved; there is an orange stripe on the side of the lower jaw. No obvious sexual dimorphism is observed in adults; males are only slightly larger than females. The wings have transformed into flippers with a dense bone structure and short but stiff feathers; this structure provides powerful propulsion in the water. The feathers are densely packed and covered with a layer of oil, enabling the animal to achieve effective thermal insulation in cold water while also ensuring waterproofing.
Taxonomy and Evolution
Taxonomically, it is the closest relative of the emperor penguin (Aptenodytes forsteri) within the genus Aptenodytes. Fossil records indicate that the genus originated in the Late Miocene–Early Pliocene (approximately 10–5 million years ago) and that its ancestors evolved from smaller penguins to adapt to the sub-Antarctic island belt. Molecular phylogenetic studies reveal that the king penguin and the emperor penguin diverged from a common ancestor approximately 1 million years ago; this divergence is associated with the harshening of marine climate conditions around Antarctica and the evolution of different reproductive strategies.
King penguin colony (Pexels-Vladimir Blyufer)
Ecology, Behaviour and Life Cycle
Habitat and Distribution
The species forms large colonies primarily on sub-Antarctic islands such as South Georgia, Crozet, Kerguelen, Heard and Prince Edward Islands. Colony selection is determined by wide, ice-free coastal strips and secure land areas for long-term chick rearing; the presence of abundant lanternfish (Electrona spp.) and krill (Euphausia spp.) in the immediate vicinity increases feeding success. They spend most of their marine life on continental shelf slopes and ocean fronts; most dives occur at depths of 100–300 metres and last between 5 and 10 minutes.
Feeding Ecology
The diet consists largely of lanternfish (particularly Electrona carlsbergi) and other small mesopelagic fish; krill (Euphausia valentini) and cephalopods, primarily squid, are among the substitute prey. Individuals typically hunt by swimming in schools at the lower limit of the marine thermocline, at depths of 100–300 metres. Adults frequently dive synchronously in loose groups of 10–50 individuals; this ‘collective shoal hunting’ increases capture efficiency by compressing fish shoals and maximizes energy yield, particularly during chick-rearing periods.
Reproductive Biology
King penguins are monogamous, with pairs typically mating with the same partner for successive breeding cycles. Although breeding can commence throughout the year in colonies, each individual's cycle lasts approximately 14–16 months, meaning pairs can only raise one chick per year. Partners incubate a single egg in turn for up to 54 days; the egg is carried on the parent's feet rather than on the snow and is protected by an ‘incubation pouch’ under the skin of the abdomen. Chicks are kept under constant parental supervision for the first 3–4 weeks after hatching, then enter the ‘nursery’ stage with other chicks in the colony. The chicks become independent within 10–13 months and return to the sea with their adult plumage. During the annual molting period, individuals fast on land for approximately 3–4 weeks; body fat reserves are vital during this period.
