Washington: An isolated population of polar bears in Greenland cleverly adapts to the reduction of sea ice, which it relies on as a platform for hunting seals, and hopes for this species in at least some parts of the warming Arctic. Provides the light of.
Populations of these hundreds of bears, part of the southeastern coast of Greenland in the Denmark Strait, are formed from hunting-frozen seawater rather than from chunks of freshwater ice that break from the giant Greenland ice sheet. Researchers said Thursday that they survived simply by reducing access to.
“They have access to glaciers (freshwater) and survive in sea ice-free fjords for more than eight months of the year. This habitat, glacier ice, is rare in most Arctic regions.” Polar scientist Christine Reidre said he was the lead author of a study published in Journal Science.
They were found to be the most genetically isolated polar bears in the world, unlike the other 19 known populations of this species. They have been almost completely isolated from other polar bears for at least hundreds of years, with evidence of occasional arrivals from other locations, but no evidence of leaving.
These bears “live on the edge of what we believe to be physiologically possible,” said evolutionary molecular biologist and research co-authors at the University of California, Santa Cruz and Howard Hughes Medical School. Beth Shapiro of the Institute said.
“These bears are not breeding. They are slow to breed and small in size. But importantly, they survive. Maybe these differences are due to genetic adaptation or due to differences in polar bear responses. I don’t know yet. Very different climates and habitats, “added Shapiro.
A total of about 26,000 polar bears are particularly plagued by climate change as rising temperatures reshape the Arctic landscape and rob them of their main prey, ringed seals, and the usual sea ice platform for hunting seals.
“The loss of Arctic sea ice remains a major threat to all polar bears. This study does not change that,” Reidre said.
The population of southeastern Greenland is geographically bordered, with jagged peaks and the Greenland ice sheet on one side and the open ocean on the other. In spring, bears roam the sea ice and glaciers, and icebergs freeze hard on the sea ice. During the summer, there is open water in front of the glacier where the glacier ice floats, from which bears hunt. This species of habitat is found only in parts of Greenland and Svalbard in the Arctic Islands.
“The use of this glacier ice has never been recorded and represents a unique behavior,” said John, a senior researcher at the Conservation Group’s Polar Bear International and a professor of biology at Old Dominion University in Virginia. Whiteman said. ..
“This study should also encourage exploration of similar habitats throughout the current polar bear range. However, glacier ice is compared to ice formed from frozen seawater in the Arctic marine canopy. It’s a minor component, “Whiteman said.
Researchers have collected genetic, motor, and population data, including satellite tracking of several bears and observations from helicopters.
“They just look like small yellow dots on white ice, or follow their trails in the snow to find them,” Reidre said.
According to Shapiro, the findings give a glimpse of how polar bears survived the previous warm season for about 500,000 years since their evolutionary division from brown bears.
“Polar bears are in trouble,” Shapiro added. “If we can’t slow down the rate of global warming that polar bears are endangered, it’s clear that the more we learn about this remarkable species, the more we can help our next survival. 50 to 100 years. “
