Researchers have recognized a particular group of polar bears described in a paper revealed immediately within the journal Science. The bears might need discovered a singular type of refuge from the consequences of local weather change in Southeast Greenland, the authors write, the place their group has develop into genetically distinct from different polar bears. Scientists at the moment are pushing to acknowledge the bears as their very own distinctive “subpopulation,” a transfer that would assist maintain them protected against potential threats like searching and habitat loss.
Over the previous decade, the researchers surveyed polar bears throughout 1,800 miles of Greenland’s jap shoreline in an effort to raised perceive the animals’ well being and actions. Though that’s a wide array, they thought they have been coping with only one group of polar bears dwelling up and down the whole coast. The bears stunned them.
After placing satellite tv for pc monitoring collars on a few of the animals, the researchers realized that bears dwelling within the southeast of Greenland saved to themselves and didn’t enterprise into locations the place they could stumble upon northeastern bears. Then, after taking a look at genetic samples, the researchers discovered that the southeastern bears are literally essentially the most genetically remoted on the planet. That signifies that they haven’t interbred very a lot in any respect with bears exterior of their group.
“It was form of an entirely surprising discovering,” says Kristin Laidre, lead creator of the brand new paper and an affiliate professor on the College of Washington. “Frankly, it was form of unintended that we realized that we have been truly coping with two subpopulations of bears, not one.”
The bears had extra surprises in retailer. The southeastern group had discovered a option to make a house for themselves in a spot that ought to have been inhospitable. Within the fjords the place they roam, sea ice is current for less than about 100 days of the 12 months. Since polar bears hunt on sea ice, that usually would have left them with lower than a 3rd of the 12 months to seek out meals.
Polar bears can quick for as much as 180 days of the 12 months, however the absence of sea ice for longer than that on this area might need left them to starve. Fortunately, the bears right here discovered one other useful resource when sea ice disappears: floating freshwater ice at a glacier entrance. Right here, they may stalk seals from their respiratory holes or sniff seals out from above after which break by way of the ice to achieve them as they usually would on sea ice.
Whereas some pockets of bears have been recognized to do that much less incessantly on freshwater ice, this group is believed to be distinctive in how a lot it will depend on it. With out the freshwater ice, their inhabitants wouldn’t actually be capable to survive right here.
The vanishing sea ice of their house is a preview of what’s to come back for the Arctic sooner or later. By the tip of the century, a lot of the icy Arctic is anticipated to see greater than 100 days a 12 months with out ice. And with no ice, there’s no seal searching and never sufficient meals for the bears. That’s what’s made the polar bear the type of poster baby for tales about impending local weather doom.
The best way that the newly found pack of polar bears has discovered a option to persist in this sort of atmosphere suggests freshwater glacial ice might function a restricted “local weather refugia” for another bears sooner or later, the researchers write. However Laidre cautions towards overselling the newly discovered bears as a hit story or a mannequin for different bears dealing with an unsure future. There are few areas with this sort of plentiful freshwater ice, known as glacial mélange, so not too many bears will be capable to depend on it. And whereas that ice has thus far been considerably spared from rising temperatures on this a part of Greenland, it would develop into more and more weak if the planet retains heating up.
That each one signifies that motion to gradual local weather change and preserve these environments will proceed to be essential for polar bears’ survival. As it’s, the worldwide polar bear inhabitants is anticipated to say no by 30 p.c over the following three generations, in line with Laidre.
She’s hopeful that if the newly noticed group of bears are designated internationally and by the nation of Greenland as a singular “subpopulation” distinct from different polar bears, they’ll get extra of the highlight in conservation efforts. The group’s genetic isolation makes them an necessary a part of sustaining genetic range amongst all polar bears — a key consider maintaining the species wholesome.
Since this group of bears was found accidentally, Laidre isn’t very positive how massive the inhabitants is. She estimates that there are maybe “a number of hundred” and that the group has doubtless been right here for a pair hundred years. The band of bears has slowly grown from migrating newcomers, too. Her analysis recognized at the very least two “immigrants” who assist maintain the inhabitants wholesome by including to the genetic pool. Laidre is hoping to launch a brand new analysis effort to give attention to this particular group of bears to get a greater concept of what number of are there and what their lives are like.