From fossils to conservation: an overview of Antarctic and sub-Antarctic penguins

Penguins are among the most distinctive birds of the Antarctic and sub-Antarctic, and their story spans from extinct “giant” fossil species to the penguins that breed today. This overview brings together evidence from fossils, ancient colony remains, chemical records, and modern monitoring to place today's population changes in a long environmental context. Fossils from Seymour Island and other Southern Hemisphere sites show that penguins have persisted for more than 60 million years, including during much warmer periods, followed by major changes as Antarctica cooled and became dominated by ice. Records from past colonies and genetic studies show that penguin populations repeatedly expanded, contracted, and shifted their ranges as sea ice and ocean conditions changed over thousands of years, highlighting how strongly penguins depend on sea ice and marine food webs. Eight Antarctic and sub-Antarctic species are assessed, summarizing current status and pressures using recent conservation assessments alongside ecological and satellite-based studies. Trends differ strongly by region: some populations, such as gentoo penguins in parts of the Antarctic Peninsula, have expanded or shifted their range, while others have declined or appear highly sensitive to changes in food availability. Looking ahead, risk is shaped by connected processes rather than warming alone. Ice-dependent species are most vulnerable where reliable sea ice is disappearing or breaking up earlier, whereas krill-dependent species face added risk where climate-driven changes in krill overlap with concentrated fishing. New tools that are improving monitoring and forecasting are highlighted, including satellite and aerial colony surveys, animal tracking, remote cameras, and improved krill mapping, alongside key remaining uncertainties such as juvenile survival, winter behavior, and the fine-scale conditions near colonies. Overall, this synthesis emphasizes a central contrast: penguins have shown resilience over deep time, yet their near-future persistence may be constrained by the speed and combined pressures of human-driven change.