Bad news for the polar bears living in the Arctic: their calorie burning rates are higher than previously thought. Researchers believe that the loss of sea ice could lead to their demise.
A study detailing the findings was published this week in the journal Science.
Scientists estimate that the planet’s sea ice levels are decreasing by 13.2% every ten years. Meanwhile, the polar bear population is on a declining trend. It is estimated that the number of bears in the Beaufort Sea has plunged 40% in just 10 years.
Lead author of the study Anthony Pagano underlined that the number and survival rates of polar bears are declining. The trend is apparently linked to the shrinking sea ice in their natural habitat.
Pagano and his team, however, couldn’t pinpoint the exact mechanisms that led to the population decline because the animals are hard to track in remote regions.
Many Polar Bears May Not Survive Winter
In the study, researchers equipped nine polar bears with GPS trackers that included cameras and accelerometers. The bears’ every move was monitored between 2014 and 2016 for about two weeks during the start of the hunting season when bears gain the most body fat.
Scientists also tracked the predators’ energy expenditure and how hard the bears had been working. Laboratory analysis of urine samples revealed that the metabolic rates of the animals exceeded scientists’ expectations by 1.6 times.
This may be because the bears consume more calories than herbivores or omnivores. Polar bears feast on energy-packed marine animals, but due to scarcity of food polar bears are forced to hunt on the land. The food they find there is not as fat-rich as the seals they are looking after and have to work harder to feed. This situation threatens their survival during harsh winters.
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