Space-based monitoring of penguin diet links sea ice, food webs, and population change

Casey Youngflesh , Christian Che-Castaldo, Mathew R. Schwaller, Michael Polito, Shawn P. Serbin, Heather` J. Lynch

Rapid environmental change poses a threat to Antarctic ecosystems. However, the spatial scale of Antarctica and its extreme environment have precluded a synoptic understanding of the links between environmental change and ecological responses. Combining tools from imaging spectroscopy, stable isotope analysis, and hierarchical statistical modeling, we developed a novel method to quantify Adélie penguin (Pygoscelis adeliae) diet from three decades of satellite imagery (1984–2013). Sea ice dynamics played a large role in regulating penguin diet across the species global range. Spatial variation in diet was additionally linked to sustained and pronounced changes in penguin abundance. This represents the first use of satellites to capture trophic dynamics at continental and decadal scales and highlights how environmental change might restructure Antarctic food webs.