Dynamic fine-scale sea-icescape shapes adult emperor penguin foraging habitat in East Antarctica

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 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.

帝企鹅（emperor penguin）是受南极预计海冰消融威胁的标志性物种，长期以来被认为会在固定冰缘（fast ice edge）觅食，推测其在繁殖季依赖大型、常年存在的冰间湖（polynyas）作为主要觅食栖息地。本研究借助新开发的精细化海冰景观数据与历史企鹅追踪数据，首次提出小型开阔水域——包括冰裂缝、冰隙（flaw leads）以及短期临时冰间湖这类此前较少被认知的区域——作为帝企鹅觅食栖息地的重要性。从东南极洲两个不同繁殖群落的47只帝企鹅身上获取的追踪数据显示，这些企鹅将23%的活动时间用于临时冰间湖，且并未利用那些被充分研究过的大型常年冰间湖，尽管后者的出现频率更高、位置更具可预测性。这些发现挑战了我们此前对帝企鹅繁殖栖息地的认知，凸显了在快速变化的极地环境中评估种群存续性时，纳入精细化海冰景观特征的必要性。