Pygoscelis penguins prefer different oceanographic and terrestrial habitats during the austral summer

Pygoscelis penguins interact with both terrestrial and marine environments, especially during the austral summer when they raise their chicks. Accessible ice-free ground spaces serve as locations for penguins to build colonies and successfully raise chicks while the surrounding marine environment serves as the foraging grounds for adult birds. Penguins must be able to navigate through the waters around their colonies to forage for Antarctic krill (Euphausia superba), their primary prey during the austral summer. Krill, whose distributions are driven partially by the surrounding physics and partially by their behaviors, must also be plentiful in the waters near the colonies to support foraging penguins. Here, we test the hypothesis that terrestrial and oceanographic variables can describe habitat suitability for Pygoscelis penguins along the West Antarctic Peninsula (WAP) during the austral summer and hypothesize that oceanographic and terrestrial covariates contribute differently to each species based on their life-histories. We built habitat suitability models using logistic regressions with a variety of datasets and determined important covariates using jackknife analysis. We developed a novel method to estimate the contribution of oceanographic and terrestrial covariates using the model terms. Models performed well across all species (area under the curve [AUC] >0.85) and predicted existing habitats as highly suitable for each species. The models also predicted new habitat for each species, including potential habitat for gentoo penguins in Marguerite Bay. While jackknife analysis suggests that terrestrial elevation is the single most important variable for some species, variables such as spring sea ice extent, prey persistence, and near-shore current velocities also were major contributors to the model across the Peninsula. Oceanographic covariates contributed the most (~65%) to chinstrap penguin habitat suitability, and the least (20%–40%) to Adélie habitat suitability. Different oceanographic variables made up most of this oceanographic term for different species, suggesting that the species select for different oceanographic habitats near breeding colonies. Understanding the major habitat suitability drivers for Pygoscelis penguins today will help us understand how habitat suitability will change in future climate conditions.