Evolution: life solves climate change worries (Introduction)

by David Turell , Friday, June 17, 2022, 17:24 (679 days ago) @ David Turell

Polar bears on glaciers don't need sea ice:

https://www.sciencealert.com/polar-bears-discovered-secretly-living-in-seemingly-inhosp...

"A secret population of polar bears in Greenland has been discovered in a seemingly impossible habitat – one that, for most of the year, lacks the floating platforms of sea ice the beasts use to hunt. The unusual group, which scientists previously thought was part of another nearby population, has been hiding in plain sight for hundreds of years.

"The bears live on the steep slopes around fjords – long and narrow coastal inlets, where glaciers meet the ocean – and hunt on a patchwork of glacial ice that breaks up in these inlets. The new discovery suggests that some polar bears, at least, may be able to adapt to sea ice disappearing as climate change worsens, the study suggests.

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"Until recently, scientists had identified 19 known subpopulations of polar bears (Ursus maritimus) living in the Arctic Circle. One of those populations spans a 1,988-mile (3,200 kilometers) stretch of the eastern coast of Greenland. But when researchers took a detailed look at this group to monitor their numbers, they realized the bears actually comprised two completely separate populations.

"Researchers analyzed 36 years' worth of tracking data from bears tagged with GPS collars and found that bears from southeast Greenland did not pass above a latitude of 64 degrees north, and bears from the northeast did not pass the same line in the other direction. Genetic sampling from individual bears confirmed that the southeastern bears were distinct from their northeastern neighbors.

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"The new southeastern population contains around 300 individuals, although determining an exact number is tricky, the researchers said. The newfound group is the most genetically diverse out of all 20 populations in the Arctic, and genetic comparisons suggest that they have been isolated from the northeastern population for around 200 years, the researchers said.

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"These sea ice conditions mimic those predicted for the rest of the Arctic by the end of the 21st century, based on previous studies, which should make the fjords unlivable for polar bears, the researchers said.

"But the southeastern bears seem to be managing surprisingly well without the sea ice.

"The researchers think that the bears are taking advantage of glacial mélange, or the bits of ice that break off the fjords' glaciers and into the sea. The bears likely use these freshwater ice patches in the same way they use sea ice to hunt, which allows them to feed themselves during the long spells when sea ice is absent from the region.

"'This suggests that marine-terminating glaciers may serve as previously unrecognized climate refugia," the researchers wrote.

"The southeastern population also lives nowhere near any human populations, and the area is believed to be too hard to reach for most hunters, which adds an extra layer of security for the bears. However, the steep slopes of the fjords can also be quite tricky for the polar bears to traverse, which may limit their movements.

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"Sea ice will continue to decline across the Arctic, which will decrease the survival odds for most polar bears, she added."

Comment: with lessening sea ice in Canada the polar population is actually increasing. The climatologist alarmists forget about the resilience of living organisms to find livable spots. The estimations of ice loss b y these folks is constantly overestimated when compared to satellite photos.