Last Millennium Adélie Penguin Mortality and Colony Abandonment Events on Long Peninsula, East Antarctica

Abstract

The Adélie penguin (Pygoscelis adeliae) is sensitive to climatic and environmental changes, and paleoecological studies of Adélie penguins and their response to climatic forcing in maritime Antarctica usually address changes on long time scales. However, on Long Peninsula, East Antarctica, we identified numerous mummified Adélie penguin carcasses and phases of rapid sediment deposition at ~750 and ~200 years BP, indicating two multidecadal mass mortality events. Based upon chronological and sedimentary evidence, we propose that the two events were caused by heavy regional precipitation, which led to the abandonment of numerous penguin subcolonies. The anomalous precipitation was likely associated with the intensification of regional meridional air transport under a zonal wave number 3 pattern. Since such atmospheric conditions correspond to present-day observations, and are expected to persist if climate change continues, the mortality events revealed in this study could become an increasing threat to penguins.