Instead, this isolated population hunts on freshwater ice near glaciers that empty into the sea, write researchers led by Kristin Laidre of the University of Washington in the journal Science. The population is also genetically different from others.
The researchers estimate that there are a few hundred of them, making them the 20th known subgroup of polar bears. Scientists have used a wealth of data, including on polar bear movements and genetics, from the last 36 years to survey the population and observe the animals in their environment.
Climate refuge?
“We knew from historical records and Aboriginal knowledge that there were some bears in this area, but we didn’t realize how extraordinary they are,” Laidre said. The region is little explored due to unpredictable weather patterns, rugged mountains and heavy snowfall.
Previously known polar bear populations largely rely on sea ice to hunt seals. However, the extent of sea ice in the Arctic has continued to decline in recent decades due to climate change. The discovery of the new population may give hope, the researchers write. Freshwater ice on glaciers that flow into the sea could serve as a “previously unknown climate refuge”.
highly isolated population
However, they caution against too much hope. The study shows how some polar bears can survive climate change, Laidre said. “But I don’t think the glacier habitat will support large numbers of polar bears. There just aren’t enough of them. We continue to expect polar bear numbers in the Arctic to decline dramatically with climate change.”
The researchers write that the now discovered population also uses sea ice that freezes directly on shore for hunting. However, this is only available in the area four months a year, until the end of May. It is the most genetically isolated population of polar bears on Earth, said co-author Beth Shapiro of the University of California. “We know that this population has been separated from other polar bear populations for at least several hundred years.”