*Free* A new population of polar bears in Southeast Greenland thrives in sea ice-free refugia

An isolated and genetically distinct population of polar bears has been discovered in Southeast Greenland, researchers report. Unlike other polar bear populations, which rely on rapidly disappearing sea ice for survival, the Southeast Greenland bears hunt year-round on the freshwater ice near marine terminating glaciers, in sea-ice conditions resembling those projected for the High Arctic in the late 21st century. The findings provide hopeful insight into polar bear resilience in the face of a warming climate. The Arctic is warming at an alarming rate – more than twice as fast as the rest of the planet. Of all the creatures threatened by Arctic warming, polar bears are particularly vulnerable. Most polar bears rely on sea ice to hunt seals. However, the occurrence and persistence of Arctic sea ice is in rapid decline. Recent forecasts of reduced polar bear distribution are based on broad-scale climate projections and do not consider the role of small-scale habitat features that could serve as climatic refugia. Combining 36 years of movement, genetic and demographic data, including traditional ecological knowledge, Kristin Laidre and colleagues discover and describe a genetically distinct, isolated population of polar bears in Southeast Greenland. Through so­phisticated habitat analysis, natural history observation, and embrace of traditional ecological knowledge, the authors also recognized a previ­ously unreported polar bear behav­ior in this group: the use of fresh ice at the marine terminal glacial fronts, also known as glacial mélange, as a platform to hunt seals year-round. Where other bear populations must move on land or migrate with receding sea ice into less productive polar areas during the ice-free season, this adaptation allows the Southeast Greenland bears to succeed in an otherwise inhospitable place. According to Laidre et al., the findings have implications for polar bear conservation, suggesting that marine-terminating glaciers, although of limited availability, may serve as previously unrecognized climate refugia. Although such glacial mélange habitats are uncommon in most of the Arctic, they are available in places like Greenland or Svalbard. In a related Perspective, Elizabeth Peacock highlights questions the study raises, including: “Will the population continue to persist in a refugium without a sea ice habitat and does southeast Greenland represent a fifth distinct ecoregion of polar bears?”