Scientists found that the changing hunting practices of a group of Greenland polar bears could be key to the species’ survival.
Polar bears have been the earliest symbols of the oncoming impacts of climate change as the species’ survival is highly dependent on the melting sea ice. But an isolated population of polar bears in Greenland have been found to be thriving by adapting their hunting practices, offering a glimmer of hope for the species in the rapidly warming Arctic.
According to a new study published in the journal Science, several hundred polar bears living in Greenland’s southeast coast have cleverly adapted by using sea ice formed from frozen seawater (or glaciers) as platforms to hunt seals, instead of relying on freshwater ice breaking off from the huge Greenland ice sheet.
Polar bears in the Arctic still depend upon icebergs that form in the open ocean to hunt. As greenhouse gas emissions and global temperature continue to rise, there is greater rate of sea loss, meaning polar bears are forced to travel longer distances to stay with the rapidly receding ice, while food supplies dwindle during winter.
Unfortunately, the glacier ice that “makes it possible for southeast Greenland bears to survive is not available in most of the Arctic,” Kristin Laidre explains, a polar scientist at the University of Washington’s Applied Physics Laboratory and lead author of the report.
The study found this group of polar bears to be the world’s most genetically isolated, and are distinct from the species’ 19 other known populations. Their genetic lineage has been almost entirely cut off from others for at least several hundred years, with limited movements and habitat.
These polar bears have the ability to fast for long periods; but must eat after 100 to 180 days to survive. Female polar bears in the southeast Greenland population also tend to weigh less than several other subpopulations, which could hinder reproduction, an issue that Laidre and her team has noted.
“These bears are not thriving. They reproduce more slowly, they’re smaller in size. But, importantly, they are surviving. It’s hard to know yet whether these differences are driven by genetic adaptations or simply by a different response of polar bears to a very different climate and habitat,” said co-author Beth Shapiro and evolutionary molecular biologist at the University of California, Santa Cruz and the Howard Hughes Medical Institute.
As Greenland continues to experience warming, changing and threatening glaciers and glacial habitats, these polar bears are still at risk of extinction. Additionally, immigrant bears could prove problematic for this small gene pool population.
“Climate action is still the single most important thing for the survival of polar bears,” Laidre states.
Read more: When Will Polar Bears Go Extinct?