Bear’s-eye view shows polar bears running out of food: Study
Saturday 03/February/2018 - 10:51 AM
Scientists say polar bears، the Arctic apex predators، need larger quantities of energy to survive than previously thought، warning that changing sea ice conditions، as a consequence of climate change، is making their prey increasingly inaccessible، according to "Press TV".
According to a new study، whose alarming results were published in the journal Science on Friday، polar bears، due to their demanding lifestyle، are more vulnerable to undernourishment than once thought.
The research reveals that the bears have greater daily energy demands، 1.6 times higher than what previous studies showed، and more than any other apex carnivores.
To conduct their study، Anthony Pagano، a research biologist at the US Geological Survey (USGS)، and his colleagues attached high-tech tracking collars to nine female polar bears they had captured on the sea ice of the Beaufort Sea in a bid to measure their efforts to find food on the thawing Arctic ice for 8 to 12 days during the springs of 2014، 2015، and 2016.
Along with tracking the polar bears’ hunting and survival activities during this critical season، the researchers measured the metabolic rates of each bear using blood and urine samples. In order to have a bear's-eye view، they also strapped GPS-camera collars to the animals to record and film their activity.
“We found that polar bears actually have much higher energy demands than predicted. They need to be catching a lot of seals،” Pagano said.
As global warming steadily thaws the amount of sea ice in the Arctic، bears will miss opportunities to catch their favorite prey—fatty، calorie-rich ringed seals—and many will weaken and starve، burning muscle mass.According to the study، the Arctic sea ice is diminishing at a rate of about 14 percent per decade، which is likely decreasing polar bears’ access to seals. It also means that their plight could be exacerbated by the need to change hunting strategies with the seasons.
Researchers said that in the crucial spring season، polar bears are mostly preying on juvenile seals. However، later in the year، after bears’ long summer fast، the young seals are older and have learned a range of survival techniques، meaning that polar bears are not able to easily catch prey as they did in the spring.
Furthermore، the summer heat causes the ice to recede، and the bears follow the ice into the Arctic basin، where there are fewer seals، meaning that bears must burn lots of energy in their long prey-finding journeys.
Consequently، this is likely to be an “important factor explaining declines in their body condition and survival” of these predators، the study said.
“As sea ice becomes increasingly short-lived annually، polar bears are likely to experience increasingly stressful conditions and higher mortality rates،” it added.
Last December، gut-wrenching footage showed an emaciated polar bear as it desperately searched for food on Baffin Island in northeastern Canada، struggling its way across the barren landscape. The clip went viral and was widely shared as a warning about the growing dangers of climate change.