International warming is famously dangerous for polar bears. The reason being easy: Sea ice offers a platform from which these hulking predators can hunt seals, their major meals supply. And local weather change is dramatically shrinking the variety of weeks every year that the Arctic oceans are lined in ice. Because of this, polar bears are spending extra time on land, the place calorie-dense meals is way much less accessible.
What meaning for the survival of those iconic creatures, nevertheless, has been one thing of a thriller. Can they address life on land?
In quest of solutions, scientists strapped recording units to twenty polar bears in Canada’s Hudson Bay, the place the ice-free interval has elevated by roughly three weeks since 1979, as a part of a research printed right this moment within the journal Nature Communications. The cameras recorded 115 hours of footage over three current years, offering a uncommon window into the land-bound lives of those animals.
The clips, a few of that are stitched collectively within the video beneath, present bears feeding on chicken carcasses (on the 2:30 mark), consuming berries and grasses (at 3:15), and chewing on some marine mammals, together with a beluga whale (at 5:00).
At instances, these gargantuan creatures — which may weigh greater than 1,500 kilos — appear to behave like canine, often play-fighting within the water (2:42) and gnawing on antlers (3:06).
(You will discover extra timestamped descriptions about what’s occurring in these clips right here.)
The clips aren’t solely cute and entertaining however extremely revealing.
“We had been amazed by the video footage,” Anthony Pagano, a wildlife biologist on the US Geological Survey (USGS) in Alaska who led the research, mentioned in an e-mail to Vox. “The video footage actually highlighted how clever these animals are through the use of completely different habits methods to outlive their time on land whereas with out entry to their major prey.”
Earlier than capturing these movies, scientists suspected that polar bears would possibly address life on land by both resting to save lots of power (i.e., burning fewer energy) or filling up on different prey, like seabirds and vegetation. These bears finally used each approaches, in response to the footage and different knowledge the scientists collected, together with measurements of motion, physique mass, and power burned. Some people laid right down to preserve power whereas others had been actively foraging for meals.
Neither strategy, nevertheless, was particularly profitable. All however one of many 20 bears misplaced weight, suggesting they’d ultimately go hungry. One particular person misplaced almost 80 kilos.
USGS/Washington State College
The research revealed that some bears took lengthy swims, which is “new and sudden for this time of 12 months,” Andrew Derocher, a polar bear knowledgeable on the College of Alberta, who was not concerned within the research, mentioned in an e-mail. “These are presumably acts of desperation,” he mentioned. “Hungry and thin bears take extra dangers than fats bears.”
Feasting on berries and different meals additionally does little to stave off starvation, the analysis reveals. “This research actually brings dwelling the message that there’s no salvation from terrestrial feeding to assist polar bears by the ice-free interval,” Derocher mentioned.
Researchers estimate that the polar bear inhabitants on this area has already fallen by 30 p.c since 1987. This research offers but extra proof that extra warming — i.e., much less ice — will solely make this already dangerous scenario worse. “With elevated land use, the expectation is that we’ll probably see will increase in hunger,” Pagano mentioned in a assertion.
USGS/Washington State College
Some polar bear populations elsewhere could also be extra resilient to warming, not less than within the brief time period, as Vox beforehand reported. Scientists have noticed a bunch of bears in southeast Greenland that hunt utilizing ice that breaks off of glaciers, which is offered year-round in some locations. (Whereas sea ice is frozen ocean water, glaciers are made from snow compressed over time into massive sheets of ice that stream like a slow-moving river.)
In a warming world, areas with glacial ice, like Greenland and Svalbard, is likely to be strongholds for the species, serving to them grasp on. It’s not precisely good information, scientists warning. As a substitute, it foreshadows the ultimate act of a tragedy, revealing the place the final remnants of a species may stay.
For now, we’re fortunate to have the ability to glimpse the lives of polar bears by their eyes. Sooner or later, there’ll probably be so much much less to see.
Correction, February 13, 12:15 pm ET: This story has been modified to mirror the total title of the publication Nature Communications.
