Specific occupation of penguins under Neoglacial cooling on the Scott Coast, Antarctica

Abstract Drastic climate change is widely believed to threaten the ecological security of penguins. Previous studies have concluded that penguins on the Scott Coast, southern Ross Sea, disappeared from ∼2000 yr BP; two opposite hypotheses of “cooling” and “warming” have been proposed for the disappearance. Here, by identifying penguin guano and remains such as eggshell fragments, bones and feathers in a sediment profile from Dunlop Island, we found that this island was not abandoned at ∼2000 yr BP. In addition, sedimentological evidence from Cape Ross deduced the permanent snow/ice cover at ∼1700 yr BP, which is consistent with a Neoglacial cooling period on the Scott Coast. We suggest that Neoglacial cooling caused the widespread abandonment of penguin colonies on the Scott Coast, by the increased coastal sea ice and/or snow/ice accumulation. However, penguins persisted at particular localities due to specific topographical or oceanic conditions shielding them from the impacts of snow and ice.