Study: Climate Change Diet Not Good for Polar Bears
2024-02-20
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1A new study suggests that the climate change diet might not be good for polar bears.
2With Arctic sea ice declining, many polar bears have to go to land for their diets during parts of the summer.
3A study looking at Hudson Bay polar bears tried to figure out if the creatures can keep their healthy weight levels on such a diet.
4Researchers found that the majority of the creatures are losing weight no matter what they do to try to increase it.
5Some bears find a lot of food - berries, eggs, sea birds and even caribou antlers.
6But such foods take a lot of effort.
7The bears use so many calories trying to eat that they end up losing weight and burning more energy than they take in, the study says.
8The findings appeared recently in the publication Nature Communications.
9Other bears go into a time of semi-hibernation. But they also lose weight.
10So either way - eating different foods or sleeping a lot - does not work, said the study's lead writer Anthony Pagano of the U.S. Geological Survey.
11Researchers found that 19 of the 20 bears studied dropped an average of 21 kilograms over three weeks of being studied.
12The research observed their calorie intake, energy use and respiration in the wild.
13The bears lost about 7 percent of their body mass on average in just 21 days, the study found.
14Polar bears try to keep up their weight in the summer after a spring when they eat a lot and gain weight.
15In the area of the Hudson Bay where researchers studied, lack of sea ice has meant polar bears are on land three weeks longer than in the 1980s, Pagano said.
16Usually, polar bears eat high-fat seals while based on sea ice near where the seals are.
17Hunting is especially good in the spring when seal pups are young and have not yet learned to swim away from the ice base, Pagano said.
18Last September, when Arctic sea ice hit its yearly low, there was about 2.6 million square kilometers less sea ice than the same time in 1979, the National Snow and Ice Data Center says.
19The United States Fish and Wildlife Service lists polar bears as a threatened species "due to the loss of its sea ice habitat."
20"This paper clearly shows that polar bears cannot adapt to the pace of change in the Arctic and that the bears are already using everything they have to stay alive,'' said University of Alberta biologist Andrew Derocher.
21Derocher was not part of the research but suggested it was important and done well.
22"This is concerning because of course it really does raise the question of when will the individual bears run out of energy," Derocher said.
23While research shows that some of the bears will survive, "other bears were basically right on the edge of where they would potentially suffer from starvation and subsequent death."
24Overall, the research shows that it is unlikely polar bears can adapt to living on land, Derocher said.
25I'm John Russell.
1A new study suggests that the climate change diet might not be good for polar bears. 2With Arctic sea ice declining, many polar bears have to go to land for their diets during parts of the summer. 3A study looking at Hudson Bay polar bears tried to figure out if the creatures can keep their healthy weight levels on such a diet. 4Researchers found that the majority of the creatures are losing weight no matter what they do to try to increase it. 5Some bears find a lot of food - berries, eggs, sea birds and even caribou antlers. But such foods take a lot of effort. The bears use so many calories trying to eat that they end up losing weight and burning more energy than they take in, the study says. 6The findings appeared recently in the publication Nature Communications. 7Other bears go into a time of semi-hibernation. But they also lose weight. 8So either way - eating different foods or sleeping a lot - does not work, said the study's lead writer Anthony Pagano of the U.S. Geological Survey. 9Losing weight 10Researchers found that 19 of the 20 bears studied dropped an average of 21 kilograms over three weeks of being studied. The research observed their calorie intake, energy use and respiration in the wild. 11The bears lost about 7 percent of their body mass on average in just 21 days, the study found. 12Polar bears try to keep up their weight in the summer after a spring when they eat a lot and gain weight. In the area of the Hudson Bay where researchers studied, lack of sea ice has meant polar bears are on land three weeks longer than in the 1980s, Pagano said. 13Usually, polar bears eat high-fat seals while based on sea ice near where the seals are. Hunting is especially good in the spring when seal pups are young and have not yet learned to swim away from the ice base, Pagano said. 14Loss of sea ice 15Last September, when Arctic sea ice hit its yearly low, there was about 2.6 million square kilometers less sea ice than the same time in 1979, the National Snow and Ice Data Center says. The United States Fish and Wildlife Service lists polar bears as a threatened species "due to the loss of its sea ice habitat." 16"This paper clearly shows that polar bears cannot adapt to the pace of change in the Arctic and that the bears are already using everything they have to stay alive,'' said University of Alberta biologist Andrew Derocher. Derocher was not part of the research but suggested it was important and done well. 17"This is concerning because of course it really does raise the question of when will the individual bears run out of energy," Derocher said. While research shows that some of the bears will survive, "other bears were basically right on the edge of where they would potentially suffer from starvation and subsequent death." 18Overall, the research shows that it is unlikely polar bears can adapt to living on land, Derocher said. 19I'm John Russell. 20Seth Borenstein reported on this story for the Associated Press. John Russell adapted it for VOA Learning English. 21_______________________________________________ 22Words in This Story 23hibernation - n. to spend the winter sleeping or resting 24respiration - n. medical: the act or process of breathing 25habitat - n. the place or type of place where an animal naturally lives 26adapt - v. to change behavior so that it is easier to live in a particular place or situation 27pace - n. the speed at which someone or something moves