Polar bears have rougher times coming as the Arctic sea ice is melting and climate change is taking its toll on them and their environment.
During an intensive new study, researchers have found that polar bears are now facing the danger of starvation as the accelerated melting of the Arctic sea ice has stranded many of them on land, unable to hunt for seals. Summer sea ice was their quick delivery of food. Now, the chances are getting slimmer that they hunt seals.
The study, conducted by researchers at the University of Wyoming tracked 43 bears for two years, between 2008 and 2009.
Previous studies had suggested that in order to conserve energy, polar bears, particularly those that are stranded on land fall into a state of walking hibernation which would protect them in the face of starvation.
The new study comes to contradict the walking hibernation hypothesis. The 43 polar bears were both shore bears and ice bears. The research team tracked the activity levels and the body temperature of the polar bears over summer months.
Both the polar bears stranded on land and those that spend time on what’s left of the Arctic ice sea displayed similar declines both in body temperature, as well as activity. However, the decline is far less pronounced than the changes that occur during the polar bears’ winter hibernation.
Continuing in a limbo of survival with less food, the polar bears are in fact facing starvation.
The University of Wyoming study, featuring in the Science journal concluded that polar bears cannot compensate in summer months for the extended food loss mirroring the loss of Arctic sea ice.
John Whiteman of the University of Wyoming and lead author of the study commented:
“We found that polar bears appear to be 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”.
Against this background, there is little room for interpretation of the walking hibernation hypothesis, according to the researchers. Far from being a type of summer hibernation, the state polar bears are found to be in is that of non-hibernating mammals which are facing long fasting periods.
It is unclear how the survival of polar bears will pan out as they are under threat due to climate change and global warming causing Arctic sea ice loss, ice-melting and the cut of food sources.
Since 2008, the U.S. Endangered Species Act included polar bears as a globally threatened species.
Photo Credits scienceprogress.org