Polar Bears Are at Higher Risk of Starvation Than Previously Thought

Sunday, 04 February 2018 - 4:19PM
Earth
Sunday, 04 February 2018 - 4:19PM
Polar Bears Are at Higher Risk of Starvation Than Previously Thought
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Wikimedia Commons/Arturo de Frias Marques
Polar bears have been a vulnerable species for some time now, and things aren't getting any brighter at the moment. 

A team of researchers recently conducted an experiment where several adult polar bears around the Beaufort Sea (just north of Alaska and Canada) were equipped with high-tech collars and metabolic tracers, to monitor how they were faring as the Arctic ice thins due to climate change. Publishing their work in the journal Science, the researchers found that the majority of these polar bears had a 50% higher metabolic rate than previously thought.

In simpler terms: these polar bears needed to eat much more than we'd previously believed, and their shrinking environment was making it more difficult to catch prey like seals as they became farther out of reach. Over half of the monitored polar bears lost body fat during the study, which could put them at risk of starvation.



Anthony Pagano, the paper's lead author and a Ph.D. candidate at University of California Santa Cruz, explained the experiment in more detail in a press statement:

Opening quote
"We've been documenting declines in polar bear survival rates, body condition, and population numbers over the past decade. This study identifies the mechanisms that are driving those declines by looking at the actual energy needs of polar bears and how often they're able to catch seals."
Closing quote


As the Arctic sea levels rise and ice melts, it compounds the problem for the polar bears - they now need to travel farther to catch prey, and all that extra traveling requires even more food that they're not finding. They have it especially rough during the summer, when they retreat north and are essentially fasting and relying on the fat they stored up earlier in the year.

Over the past decade, researchers with the U.S. Geological Survey (which Pagano is also involved with) have observed the population of polar bears dip by about 40%, but the inhospitable environment made it difficult to measure exactly how the bears were navigating on the ice as the warming oceans continue to melt them. Pagano concludes:

Opening quote
"We now have the technology to learn how they are moving on the ice, their activity patterns, and their energy needs, so we can better understand the implications of these changes we are seeing in the sea ice."
Closing quote


As for how we could help: we mostly know what needs to be done about climate change, we just need to actually do it.
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