Isolated polar bear populations have been found in southeastern Greenland 1, which is devoid of sea ice for most of the year. In fact, the polar bear with the scientific name Ursus maritimeus, usually requires ice to survive.
On the one hand, this discovery raises hopes that some members of this species can survive the significant ice loss conditions caused by climate change.
The researchers identified a genetically distinct sub-population living in the fjords of southeastern Greenland, which is surrounded by mountains and ice sheets to the west, and oceans to the east. Because this region is so far south, the sea ice sheet lasts only about 100 days each year.
Polar bears need access to Arctic sea ice to hunt seals. So, with sea ice reduced in the region due to global warming, these animals are expected to be close to extinction by the end of this century.
But, as quoted from Nature, isolated sub-populations have found a way to hunt without ice. The group, consisting of 27 adult females, has adapted to hunting on ice that has split glaciers (called a glacial mélange).
The research team used genetic analysis to determine that this population has been isolated from other polar bear populations along the east coast of Greenland for at least 200 years.
Tracking data from the tagged bears, confirming that they haven't moved far. For example, when group members emerge from a fjord, the ice platform on which they sit is sometimes caught in the rushing current that flows down the east coast of Greenland.
"Whenever this happened, they would get caught in the current that was tearing the shore and they would literally jump, swim ashore and walk back home," said lead author Kristin Laidre, an animal ecologist at the University of Washington in Seattle.
The presence of this small population in conditions of low sea ice cover suggests it is possible the species could survive, even as the sea ice retreats further north each year.
"This genetically distinct group of small bears may explain how polar bears as a species can survive in the ice-free Arctic," Laidre said.
