Abstract: The emperor penguin, an iconic species threatened by projected sea ice loss in Antarctica, has long been considered to forage at the fast ice edge, presumably relying on large/yearly persistent polynyas as their main foraging habitat during the breeding season. Using newly developed fine-scale sea icescape data and historical penguin tracking data, this study for the first time suggests the importance of less recognized small openings, including cracks, flaw leads and ephemeral short-term polynyas, as foraging habitats for emperor penguins. The tracking data retrieved from 47 emperor penguins in two different colonies in East Antarctica suggest that those penguins spent 23% of their time in ephemeral polynyas and did not use the large/yearly persistent, well-studied polynyas, even if they occur much more regularly with predictable locations. These findings challenge our previous understanding of emperor penguin breeding habitats, highlighting the need for incorporating fine-scale seascape features when assessing the population persistence in a rapidly changing polar environment.

Abstract: The spatial ecology of seabirds has greater precedence today than ever before because of impacts on the marine environment from human exploitation, pollution, and climate change. Specific life history traits make seabirds particularly sensitive to these impacts, currently driving many species to unsustainable population declines. To evaluate the risk posed by human activities, we need integrative studies on seabird abundance, distributions, and movements in relation to the biophysical marine environment. Also interpreting the limits of these relationships is fundamental to understanding historical constraints and behavioural adaptations of seabirds that are shaped by evolutionary processes. In this Theme Section, we assembled 4 review papers and 10 case studies that highlight some of the latest techniques to study seabird spatial ecology. This includes the application of tracking tags, ship-based surveys, and remotely sensed environmental data, to characterize seabird movement patterns, fine scale behaviour, and overall distribution combined with measures of the oceanic habitats to enhance our understanding of the functional role that seabirds play. Overall, this knowledge is crucial for understanding and predicting the impacts that fisheries, climate change and pollution are exerting on marine ecosystems and will provide opportunities for developing marine protected areas, conservation action plans and species management.