Strange, isolated polar bear colony found in Greenland

Polar bears on a glacier or freshwater ice at 61 degrees north latitude in southeastern Greenland in September 2016.

Polar bears on a glacier or freshwater ice at 61 degrees north latitude in southeastern Greenland in September 2016.
photo: Thomas W. Johansen/NASA Ocean Melting Greenland

Researchers have identified a previously unknown population of polar bears living in isolated areas in southeastern Greenland. Polar bears look for seals in fjords, freshwater ice shelves, not on rapidly receding sea ice like other polar bear species.

New report in the journal science The population is described and the total number of polar bear groups now known to range from 19 to 20 confirms that this is a single population.The group consists of Hundreds of bears, and females tend to be smaller than in other populations.

“Polar bears in southeastern Greenland are the most genetically isolated polar bears on the planet. They are different from all 19 other polar bear subpopulations in the Arctic, and more so than any other pair of polar bear subpopulations,” said University of Washington polar scientists, Christine Ryder, lead author of the study, said in an email to Earther. “They’ve been separated for hundreds of years, and likely remained a small group.”

Scientists have been building research stations in Greenland for years, collaring bears and monitoring them to confirm their fitness and isolation. This new group was tracked from 2015 to 2021, Laidre said.

Three adult polar bears in southeastern Greenland in April 2015. They use sea ice for a limited time.

Three adult polar bears in southeastern Greenland in April 2015. They use sea ice for a limited time.
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 article in Science to accompany Ledley’s research. She explained that some posts online suggested the isolated bear population could be a “thriving” population as they found a new way to hunt. But Peacock did not believe that would be the case.

“Plasticity usually refers to a person’s ability to, you know, use different behaviors … so, ‘I can figure out how to kill a walrus, or I can figure out how to fish,'” she said. “Natural selection adapts over time … assuming polar bears have enough time to change what they’re doing in response to natural selection.”

Unfortunately, the impact climate change It’s happening faster than many polar bears can reproduce.

The dots on the map on the left show where the Greenland polar bear samples were collected. The new southeastern Greenland population (shown as red dots) lies between latitudes 60 and 64 degrees north.

The dots on the map on the left show where the Greenland polar bear samples were collected. The new southeastern Greenland population (shown as red dots) lies between latitudes 60 and 64 degrees north.
picture: Laidre et al/Science

In her article, Peacock points out that other known polar bear populations have shown signs of plasticity, such as nesting inland far from depleted sea ice or finding different types of prey when the usual seal diet isn’t abundant. With ice at the poles melting, there are questions about whether glacier hunting can continue in the future.Generations of polar bears approx. up to 10 years, but climate change is affecting ice much faster than that. Researchers worry that the new behavior may not survive because the climate crisis is rapidly depleting the Arctic’s ice.

“We don’t know if they’re thriving. We don’t know if the population is stable or stuck. That’s going to require more research,” Ryder said in an email. To really determine how these populations are doing in the face of climate change, scientists must study how well they survive by tagging adult female polar bears and studying them over three to four years.

“Glacier ice may help a small number of polar bears survive longer in a warming climate and may be important for the persistence of the species (meaning preventing extinction), but it does not apply to the vast majority of polar bears,” she said. “Monitoring these bears in the future may tell us more about the future of this species.”

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