Penguins That Eat Krill

11 penguin species include krill in their diet: Adelie Penguin, Chinstrap Penguin, Eastern Rockhopper Penguin, Emperor Penguin, Erect-crested Penguin, Macaroni Penguin, Magellanic Penguin, Northern Rockhopper Penguin, Royal Penguin, Snares Penguin, Western Rockhopper Penguin. Diet is one of the most revealing lenses for understanding penguin ecology because what a penguin eats determines how deep it dives, how far it travels from the colony, and how vulnerable it is to changes in ocean productivity.

Krill is a critical prey item because it sits at a key point in the Southern Ocean food web. Penguins that depend heavily on krill are directly exposed to fluctuations in prey abundance driven by ocean temperature, current patterns, and competition with commercial fisheries. A bad krill year does not just mean hungry adults — it means failed breeding, abandoned chicks, and population-level consequences.

The species in this dietary group range across Antarctica, South Shetland Islands, South Orkney Islands, South Sandwich Islands and span sizes from Eastern Rockhopper Penguin (58 cm) to Emperor Penguin (130 cm). Larger species generally dive deeper and can access prey at greater depths, while smaller species are restricted to shallower foraging zones. This size-depth relationship means that even species eating the same prey type may be fishing at completely different levels of the water column.

Conservation attention for krill-dependent penguins increasingly focuses on marine protected areas and fishery management. Erect-crested Penguin, classified as Endangered, is the most vulnerable species in this dietary group and illustrates how prey dependence can amplify other threats like habitat loss and climate change.