What is the main prey of Adélie penguins during much of the Antarctic breeding season?

Antarctic krill are the main prey of Adélie penguins during much of the Antarctic breeding season.

Adélie penguins feed on small marine animals, especially Antarctic krill, a shrimp-like crustacean that forms a major part of the Southern Ocean food web. They also eat fish and other crustaceans when available. Adults collect food at sea and return to colonies to feed their chicks.

Krill availability is closely linked to sea ice because krill graze on algae associated with ice-covered waters. This creates an important connection between sea-ice conditions and penguin breeding success. When local food supplies are poor, adults may need to travel farther or spend more time foraging.

Adélie penguins breed along the Antarctic coast and nearby islands. Their diet is sometimes confused with that of penguins that specialize more heavily in fish. Diets vary with location, season, and ocean conditions, so “main prey” does not mean krill is their only food. The species is an important indicator of changes in parts of the Antarctic marine ecosystem.