What Makes This Population Special
The newest identified population
The Southeast Greenland polar bear sub-population is the 20th to be identified. Its existence was unknown and unexpected by western scientists until a multi-year and cross-disciplinary research effort led by Kristin Laidre of the University of Washington began conducting a population assessment of bears in this region. Indigenous Greenlandic subsistence hunters advised the researchers that polar bears could be found year-round in glacial fjords all the way to the country’s southernmost tip and provided Laidre and her team with hand-drawn maps of the area. Using that information as a guide, the researchers found previously unstudied bears living at the foot of glaciers near the abandoned southeastern settlement of Skjoldungen-Timmiarmiit.
In a 2022 paper in the journal Science, Laidre and colleagues described flying over the area and discovering several bears in the fjords, as predicted by their Inuit collaborators. On subsequent visits – which, because of the remoteness of the area, took several years to complete – the scientists added more details, including the realization that the bears are physically isolated and genetically distinct from other populations. In the Science paper announcing the discovery, Laidre and colleagues proposed that the bears of Southeast Greenland should be considered a new sub-population, which was formally endorsed by the Polar Bear Specialist Group in 2024.
Isolation from other populations
Laidre and colleagues attached satellite collars to 27 bears in the area and compared those bears’ movements to 36 years of tracking data from bears in East Greenland. They found that bears south of 64 degrees N did not interact with those from farther north at all; nor did bears from above that line of longitude venture south. Instead, bears in Southeast Greenland made localized movements in fjords, with some remaining in one fjord for years while others moved between adjacent fjords, traveling over mountains via the ice sheet and peripheral glaciers. On average, each bear occupied a home range as small as five or six square miles, significantly less than the approximately 900-square-mile home ranges of bears farther north in Greenland. Early data suggests that female polar bears may be smaller, and give birth to fewer cubs, than those in other populations.
Furthermore, DNA analysis of bears from SE Greenland revealed that the difference between this group of bears and its nearest genetic neighbor is greater than that observed for any of the 19 previously known polar bear populations and that the area’s bears have been genetically isolated for about 200 years.
Laidre and colleagues hypothesize that, two or more centuries ago, the Eastern Greenland Coastal Current, which flows southward along the island’s Atlantic shore, carried some polar bears on large ice floes, from which they were able to reach land. Hemmed in by the Greenland ice sheet to the west, the ocean to the east, and mountains on most sides, the descendants of those bears have continued to interbreed, most likely with an occasional influx of outside genetic material: the researchers found two bears whose DNA profile differed from the others, indicating they were recent arrivals from Northeast Greenland and the Southern Beaufort Sea/Chukchi Sea region, both presumably also carried along on drifting ice.
Staying on land, or close to it
Every other sub-population of polar bears is almost wholly reliant on sea ice as a platform on which to travel and from which to hunt seals. The bears of Southeast Greenland are the exception.
As previously noted, the Eastern Greenland Coastal Current carries ice floes south along the east coast; however, those floes bypass the fjords, and for eight months of the year the current is too strong and the ice too broken for it to be a safe, usable habitat. The bears do use sea ice for roughly four months a year, from February to late May, when the ice is at its thickest, but they remain close to the coast when they do so, rarely venturing more than 12 miles (20 kilometers) from shore.
During the other eight months of the year, they spend much of their time hunting ringed seals from small floes of freshwater ice that have broken off from glaciers fed by the massive Greenland ice sheet.
Although SE Greenland bears are homebodies compared to other bears, they do move between fjords, climbing up mountains and glaciers to exit one fjord and then literally sliding down slopes into a neighboring fjord.
On their occasional forays out onto the sea ice, some bears do end up being carried away on floes by the strong current, but all those recorded as doing so have been able to hop off and return to shore.
Significance for Polar Bear Conservation
The discovery of a polar bear population that is not dependent on sea ice led to some speculative comments about whether this meant the species could survive the changes caused by a warning climate after all.
However, while this does add to evidence that, in very specific situations, some polar bear populations may show unexpected resilience in the face of climate change, polar bears will not be switching to a glacier ice environment. For one thing, such habitat is present in only a small part of the species’ circumpolar range; and glacier ice, like sea ice, is in retreat across the globe.