While a warming climate is lessening polar bears' food options, the animals are having trouble adapting to what they have been left with.
According to BBC News, authors of a study published in the journal Science suggest polar bears simply not cut out for a warmer climate. They examined how the bears conserve energy when food was low, like it is in warmer conditions, and found discouraging results.
"We found that polar bears appear unable to meaningfully prolong their reliance on stored energy, confirming their vulnerability to lost hunting opportunities on the sea ice - even as they surprised us by also exhibiting an unusual ability to minimize heat loss while swimming in Arctic waters," study lead author John Whiteman, a doctoral student at the University of Wyoming and project leader, said in a press release.
The polar bear's primary prey is seal, which they snag from the water while stationed on sea ice. However, the warming global climate is causing that ice to melt swiftly and the after affects are clearly hurting polar bears.
For their study, the researchers wanted to test the theory of "walking hibernation," which entails a low output of energy to compensate for a lighter diet.
"Their metabolism is very much like a typical food limited mammal rather than a hibernating bear," Whiteman told BBC News. "If you or I were to be food-limited for weeks on end we would look like the bears' data."
While polar bears were also discovered to have a unique internal system that allows them to swim in water, the seals have to be in the water for the bears to try and go get them.
"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, it was very surprising," Whiteman said. "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.
"We think this data also points towards their eventual decline."
