A strange isolated group of polar bears discovered in Greenland

A strange isolated group of polar bears discovered in Greenland

A Southeast Greenland polar bear on a glacier or freshwater ice at 61 degrees north in September 2016.

A Southeast Greenland polar bear on a glacier or freshwater ice at 61 degrees north in September 2016.
Photo: Thomas W. Johansen/NASA Oceans melt Greenland

Researchers have identified a previously unknown population of polar bears living in the isolation of southeast Greenland. Bears hunt seals in fjords, on freshwater ice shelves, rather than on rapidly receding pack ice like other polar bear species.

A new report in the magazine Science described the population, which now brings the total number of known polar bear groups from 19 to 20. Scientists knew that some polar bears might be in this area based on historical records and knowledge of indigenous communities in the area. ‘Arctic, and they were finally able to confirm that it is a distinct population. The group consists of a few hundred bears, and females tend to be smaller than those of other populations.

“Polar bears in southeast Greenland are the most genetically isolated polar bears on the planet. They are distinct from the other 19 Arctic polar bear subpopulations and more distant from neighboring subpopulations than any other pair,” said Kristin Laidre, a University of Washington polar scientist and lead author. study, in an email to Earther. “They’ve been separated for a few hundred years and have probably always been a small population.”

Scientists have worked for years to establish research stations in Greenland, bond the bears and monitor them to confirm their adaptability and isolation. Laidre said this new group was followed from 2015 to 2021.

Three adult polar bears in southeast Greenland in April 2015. They use sea ice for the limited time it is available.

Three adult polar bears in southeast Greenland in April 2015. They use sea ice for the limited time it is available.
Photo: Kristin Laidre/University of Washington

Elizabeth Peacock, an assistant professor at Emory University School of Medicine and a polar bear expert, wrote a perspective piece to accompany Laidre’s research in the journal Science. She said some online posts have hinted that this group of isolated bears could be a “thriving” population as they have found a new way to hunt. But Peacock, she’s not convinced that’s the case.

“Plasticity usually refers to an individual having the ability to, you know, use different behaviors…so, ‘I can figure out how to kill a walrus or I can figure out how to catch fish,'” he said. she declared. “Natural selection is about adapting over time…it assumes polar bears have enough time to change what they’re doing to respond to natural selection.”

Unfortunately, the effects of climate change are happening faster than many polar bears can reproduce.

The dots on the left map indicate where samples of Greenland polar bears were collected.  The new population in southeast Greenland, represented by red dots, is located between 60 and 64 degrees north.

The dots on the left map indicate where samples of Greenland polar bears were collected. The new population in southeast Greenland, represented by red dots, is located between 60 and 64 degrees north.
Image: Laidre et al./Science

In his article, Peacock pointed to other known polar bear populations that have shown signs of plasticity, such as nesting further inland away from sea ice depletion or hunting different types. of prey when their usual seal diet is not as plentiful. One wonders if glacier hunting will continue to be possible in the future, as the ice is melting at both poles. Generations of polar bears are on the verge 10 years, but climate change is affecting the ice at a much faster rate than that. Researchers fear this new behavior will carry over as the climate crisis rapidly depletes the ice in the Arctic.

“We have NO IDEA if they are thriving. We don’t know if the population is stable or struggling. This will require more research,” Laidre said in an email. to climate change, scientists will need to study the survival of adult female polar bears by tagging and studying them for three or four years.

“Glacial ice may help a small number of polar bears survive longer under global warming, and may be important for species persistence (i.e. preventing extinction), but it is not available to the vast majority of polar bears,” she said. “Future monitoring of these bears can perhaps tell us a bit more about the future of the species.”

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