Polar bears struggling to adapt to longer ice-free Arctic periods

Polar bears use the ice that stretches throughout the ocean floor within the Arctic throughout colder months to assist them entry their most important supply of prey — fatty ringed and bearded seals.

Within the hotter months when the ocean ice recedes, they might be anticipated to preserve their vitality and even enter a hibernation-like state. 

However human prompted local weather change is extending this ice-free interval in components of the Arctic — which is warming between two and 4 occasions sooner than the remainder of the world — and forcing the polar bears to spend an increasing number of time on land. 

New analysis 20 polar bears in Hudson Bay means that with out sea ice they nonetheless attempt to discover meals. 

“Polar bears are inventive, they’re ingenious, , they are going to search the panorama for methods to attempt to survive and discover meals assets to compensate their vitality calls for in the event that they’re motivated,” Anthony Pango, a analysis wildlife biologist with the US Geological Survey and lead writer of the examine, instructed AFP.

The analysis, revealed within the journal Nature Communications, used video digicam GPS collars to trace the polar bears for three-week intervals over the course of three years within the western Hudson Bay, the place the ice-free interval has elevated by three weeks from 1979–2015, that means that within the final decade bears had been on land for about 130 days.

The researchers discovered that of the group, two bears certainly rested and diminished their whole vitality expenditure to ranges much like hibernation, however the 18 others stayed lively.

The examine mentioned these lively bears could have been pushed to proceed to search for meals, with particular person animals documented consuming quite a lot of meals together with grasses, berries, a gull, a rodent and a seal carcass.  

Three ventured off on lengthy swims — one travelled a complete distance of 175 kilometres (greater than 100 miles) — whereas different bears frolicked enjoying collectively or gnawing on caribou antlers, which researchers mentioned was like the way in which canines would possibly chew bones. 

However finally the researchers discovered that the bears’ efforts to seek out sustenance on land didn’t present them with sufficient energy to match their regular marine mammal prey.

Nineteen out of the 20 polar bears studied misplaced weight in the course of the interval per the quantity of weight they might lose throughout a interval of fasting, researchers mentioned.

That implies that the longer polar bears spend on land, the upper their threat for hunger.

– Trigger for alarm –

“These findings actually assist the prevailing physique of analysis that is on the market, and that is one other piece of proof that actually raises that alarm,” Melanie Lancaster, senior Arctic species specialist for the World Wildlife Fund, who is just not related to the examine, instructed AFP. 

The world’s 25,000 polar bears remaining within the wild are endangered primarily by local weather change. 

Limiting planet-warming greenhouse gases and retaining world warming below the Paris deal goal of 1.5 levels Celsius above pre-industrial ranges would possible protect polar bear populations, Pango mentioned.

However world temperatures — already at 1.2C — proceed to rise and sea ice dwindles.

John Whiteman, the chief analysis scientist at Polar Bears Worldwide, who was not concerned within the examine, mentioned the analysis was priceless as a result of it straight measures the polar bears’ vitality expenditure in the course of the ice-free intervals. 

“As ice goes, the polar bears go, and there’s no different resolution apart from stopping ice loss. That’s the solely resolution,” he instructed AFP. 

rgl/klm/gv

Initially revealed as Polar bears struggling to adapt to longer ice-free Arctic intervals