The Antarctic Peninsula, one of the planet's most rapidly warming regions, affords us a unique opportunity to understand the impacts of climate change on ecological systems. Life history differences among the congeneric and sympatrically-breeding chinstrap, Adélie, and gentoo penguins significantly influence responses to climate change. The Antarctic Site Inventory project has been monitoring these penguins since 1994 at over 125 locations. We use this data, along with a series of statistical models designed to overcome the opportunistic nature of the data collection, to understand the regional scale dynamics of these three populations during a period of rapid environmental flux.
We find clear regional-scale patterns of population change including a sharp decline in the sea-ice-dependent Adélie penguins along the central-western Antarctic Peninsula and concurrant increases and range expansion in populations of the more sub-Antarctic gentoo penguin. Declining Adélie penguin populations are strongly correlated with declining mid-winter sea ice whereas gentoo penguin increases are correlated with declining sea ice during the breeding season. Additional analyses of penguin diet and phenotypic plasticity in breeding phenology all support our conclusion that gentoo penguins are clear climate change winners in this region, while Adélie penguins are losing ground as the Peninsula continues to warm.