Polar bears are susceptible to climate warming because of their dependence on sea ice, which is declining rapidly. We present the first evidence for a genetically distinct and functionally isolated group of polar bears in Southeast Greenland. These bears occupy sea-ice conditions resembling those projected for the High Arctic in the late 21st century, with an annual ice-free period that is >100 days longer than the estimated fasting threshold for the species. Whereas polar bears in most of the Arctic depend on annual sea ice to catch seals, Southeast Greenland bears have a year-round hunting platform in the form of freshwater glacial mélange. This suggests that marine-terminating glaciers, although of limited availability, may serve as previously unrecognized climate refugia. Conservation of Southeast Greenland polar bears, which meet criteria for recognition as the world’s 20th polar bear subpopulation, is necessary to preserve the genetic diversity and evolutionary potential of the species.

中文翻译：

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冰川冰支持了在 21 世纪后期海冰条件下持续存在的独特且未记录的北极熊亚种群

北极熊很容易受到气候变暖的影响，因为它们依赖于正在迅速减少的海冰。我们提供了格陵兰东南部一组基因不同且功能孤立的北极熊的第一个证据。这些熊占据的海冰条件类似于 21 世纪后期北极高地的预测条件，每年的无冰期比该物种估计的禁食阈值长 100 天以上。北极大部分地区的北极熊依靠每年的海冰捕捉海豹，而东南格陵兰熊则以淡水冰川混合物的形式拥有全年的狩猎平台。这表明终止海洋的冰川，虽然可用性有限，但可能作为以前未被认可的气候避难所。保护东南格陵兰北极熊，