Polar Bears Are Not Able To Cope With Food Loss In Warmer Arctics

Polar bears are failing to cope with loss of food in the warm summers of the Arctic, according to bbc.

So far, scientists thought that the animals would enter into 'walking hibernation' when they do not have prey. Yet, new research shows that they just starve when it is hotter and the food is less.

As far back as in 2008, they were thought to be a threatened species in the US. The Secretary of the Interior had noted that decline in sea ice was a big threat for them. Due to increased melting of ice, they have less seals, which makes them struggle to find their food.

Rising global temperatures can increase the "sea ice retreat, which can reduce polar bears' opportunities to hunt seals" according to ibtimes.

Although some scientists argued that due to lower calorie intake, the bears can just enter into a "low-activity state" or "walking hibernation", the scientists started a dangerous and expensive trial,l fixing "satellite collars and surgically implanted logging devices" to record their movements as well as physiological details. Over two dozen bears in the Beaufort Sea, north of Alaska, were studied.

However, they discovered that in the hotter summers, they did not "slow down, they simply starved".

"Their metabolism is very much like a typical food limited mammal rather than a hibernating bear," said John Whiteman from the University of Wyoming, the paper's lead author. "If you or I were to be food-limited for weeks on end we would look like the bears' data."

However, they are able to manage swimming in cold water.

"They have this ability to temporarily allow the outermost portion of the core of the body to cool off substantially and this protects the innermost vital organs - there was not an expectation of that. Still, the lack of food and their inability to slow their metabolism is worrying.

"We've uncovered what seems to be a fascinating adaptation for swimming in cold arctic waters, but I don't think that is going to play as big a role in determining their fate as the loss of hunting opportunities will," said Whiteman. "We think this data also points towards their eventual decline."

The experiment has been expensive.

"The cost was extremely high for such a study but our results are indisputable so I doubt anyone will feel the need to repeat this," said Prof Merav Ben-David, from the University of Wyoming, another author.

The paper has been published in the journal Science