A new population of polar bears has been discovered in an ice-free corner of Southeast Greenland, according to a study published today in the journal Science. Polar bears typically rely on sea ice to act as a floating platform while catching seals and other prey, but this genetically distinct population manages to thrive in a region with little-to-no ice, much to the interest of the researchers.
Scientists from the University of Washington in Seattle and the Greenland Institute of Natural Resources reached the findings through a combination of genetic data, traditional ecological knowledge from local Indigenous people, and satellite imagery that captured over 30 years of observations.
They estimated that a “few hundred” polar bears make up this population in Southeast Greenland, a similar size to the 19 currently known subpopulations. However, the Southeast polar bears do have substantially fewer adult females with newborn cubs in the spring compared to other populations.
After collecting samples from a few individuals, they discovered that the population was genetically distinct from all subpopulations of the species in the wild. In fact, the Southeast Greenland bears were found to be the most genetically isolated polar bears in the Arctic.
Satellite imagery backed up this point, showing that the Southeast population had no interaction with bears living in Northeast Greenland.
Altogether this indicates that the Southeast population is isolated and genetically distinct from all other polar bear populations. However, perhaps most remarkable about this research was the new behavior documented by the team.
Southeast Greenland is sea ice-free for more than 250 days per year, exceeding polar bears’ ability to fast for over 100 days. However, this population doesn’t go hungry. Instead of using sea-ice platforms to hunt, they use fresh ice at the marine terminal glacial fronts, also known as glacial mélange, as a platform to hunt seals year-round. This is behavior that's never been reported before.
The portion of Southeast Greenland where this new population can be found has similar conditions to those projected for the late 21st century in the upper Arctic after much of the ice has been impacted by climate change.
Since the Southeast Greenland population has adapted to living in a largely ice-free environment, the researchers hope that it could be a positive indication of how the polar bear population will cope with the climate crisis.
A study published in 2020 argued that polar bears could become extinct by the end of this century, primarily as a result of shrinking sea ice disrupting their hunting habits. Different populations will suffer more acutely according to how the changing environment affects their diet and behavior.
It’s hoped that perhaps this new Southeast population, with its never-before-seen hunting technique, might be able to weather the storm a little better than others — but there are no promises.