Description: It is the largest living penguin, reaching up to 120 cm in height and 46 kg in weight. Adults have a bluish-gray back and a whitish belly, separated by a black longitudinal lateral line extending from the neck to the flipper area; the head has a black cap and an orange-yellowish ear area that expands into a pale yellow toward the chest; long, slightly curved beak with a pinkish-orange spot at the base of the jaw; sparsely feathered tarsi and dark gray legs. Juveniles are characterized by having a whitish to grayish ear area and dark gray at the base of the jaw. Chicks have their bodies covered by gray down and a black cap on their head like a helmet.

Possible Confusions: The only similar species is the King Penguin (Aptenodytes patagonicus), but it differs by being smaller (approximately 95 cm in height and up to 15 kg in weight); adults have a smaller ear patch, bright orange with well-defined black edges, which continues through a thin line to the neck; the beak is relatively longer, less curved, and with the pinkish-orange spot on the jaw more expanded; the tarsi are naked. In juveniles, the ear patch is yellow. Chicks have their bodies covered in brown down.

Geographical Distribution: Circumpolar, restricted to Antarctica between 66°-78° S.

Habitat: Marine and pelagic during the non-breeding season (December to April approximately); on the sea ice shelf surrounding the Antarctic continent during the breeding season (April to December approximately).

Behavior: They are great divers. Although they stay submerged within the first 50 meters, some individuals can dive for 18 minutes and reach depths of up to 500 meters. They spend most of their life in breeding colonies on the sea ice platform.

Diet: Mainly fish and crustaceans (krill), but they also include cephalopods (squid) in their diet, which are captured by pursuit during diving.

Reproduction: It is the only penguin species that nests in the Antarctic winter and also the only one that lays a single egg. During autumn, Emperor penguins leave their pelagic life and enter the sea ice toward the breeding colony. They do not build nests. Females lay the egg, and the incubation occurs beneath a fold of skin on the males´ feet. During the incubation period, which lasts approximately two months, females return to the sea to feed, while the male remains unfed and exposed to the harsh Antarctic climate. The males of the breeding colony stay grouped in circles, and individuals move slowly from the periphery to the center and vice versa, a behavior that allows them to increase the temperature at the center of the group and reduce the energy costs of incubation. Almost at the same time the eggs hatch, females return to the colony to feed the chicks. From that moment on, both parents take turns returning to the sea to find food. As the chicks´ demand for food increases, both parents must return to the sea; from then on, the chicks group together to form nurseries while being cared for by a few adults. In approximately December, the chicks´ down is replaced by adult plumage; this coincides with the melting of the sea ice due to rising temperatures. After this period, the adults resume their pelagic life, and the chicks are already able to feed themselves.

Threats and Conservation Status: Due to the reduction of sea ice, changes in the distribution and abundance of prey due to global warming, and the impact of human activity, the Emperor Penguin is classified as "Near Threatened (NT)" according to BirdLife International (2020).

Author of this Compilation: María Alejandra Sosa - 11/05/2021

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