The polar bears were found to be physically and genetically different from other species, which the researchers believe is due to their being surrounded by mountains, the Denmark Strait, the East Greenland Coastal Current and the Greenland Ice Sheet.
Body measurements suggest that adult females are smaller than in most regions. They also have fewer young, possibly reflecting the challenge of finding mates in the remote landscape of fjords and mountains.
Also, unlike other polar bears, the community prefers to stay in one place rather than venturing far across the sea ice to hunt. Satellite tracking showed that when 27 bears accidentally drifted 120 miles on ice floes caught in a coastal current, they swam ashore and headed home.
“They are the most genetically isolated population of polar bears in the world,” said co-author Professor Beth Shapiro of the University of California at Santa Cruz and a Howard Hughes Medical Institute researcher.
“We know that this population has been separate from other polar bear populations for at least several hundred years and that its population size has remained small throughout this time.”
“A Steady Supply of Ice Cream”
The landscape means the south-east Greenland bears only have access to sea ice for four months, between February and late May, but for the remaining two-thirds of the year they hunt seals from chunks of freshwater ice that break off the Greenland ice sheet.
However, researchers say that the fact that bears can survive suggests that glaciers that leave the sea, and particularly those that regularly calve ice into the ocean, could become climate change hotspots as the ocean ice melts.
“Even with rapid changes in ice sheet, this area of Greenland has the potential to continue producing glacial ice for a long time to come, with a coastline that could resemble today’s,” said co-author Twila Moon, associate principal scientist at US National Snow and Ice data centre.
“These types of glaciers also exist elsewhere in the Arctic, but the combination of fjord shapes, the high production of glacial ice and the very large ice reservoir available from the Greenland ice sheet currently provides a constant supply of glacial ice.”
A separate study from the University of California found that 10 percent of brown bears’ DNA comes from polar bears, with researchers suggesting the breeds may start mating again if climate change brings their habitats closer together.
The results were published in the journal Science.
https://www.telegraph.co.uk/news/2022/06/16/newly-discovered-population-polar-bears-could-dodge-impacts/ Newly discovered population of polar bears could dodge impacts of climate change