EBN- Some polar bears face starvation as the Arctic sea ice melts because they are unable to adapt their diets to living on land, scientists have found.
The iconic Arctic species normally feed on ringed seals that they catch on ice floes offshore.
But as the ice disappears in a warming world, many bears are spending greater amounts of time on shore, eating bird’s eggs, berries and grass.
However the animals rapidly lose weight on land, increasing the risk of death.
The polar bear has become the poster child for the growing threat of climate change in the Arctic, but the reality of the impact on this species is complicated.
While the number of bears plummeted up until the 1980s this was mainly due to unsustainable hunting.
With greater legal protection, polar bear numbers have risen. But increasing global temperatures are now seen as their biggest threat.
That’s because the frozen Arctic seas are key to their survival.
The animals use the sea ice as a platform to hunt ringed seals, which have high concentrations of fat, mostly in late spring and early summer.
But during the warmer months many parts of the Arctic are now increasingly ice-free.
This allowed the scientists to record the animals movements, their activities and what they ate.
In the ice-free summer months, the bears adopted different strategies to survive, with some essentially resting and conserving their energy.
The majority tried to forage for vegetation or berries or swam to see if they could find food.
Both approaches failed, with 19 of the 20 bears in the study losing body mass, by up to 11% in some cases.
“Polar bears are not grizzly bears wearing white coats,” said co-author Charles Robbins from the Washington State University Bear Center.
“They’re very, very different.”
Two of the three bears that took to the water found carcasses of dead animals. But they spent only a short time eating.
“It really suggests to us that that these bears can’t eat and swim at the same time.”
