Scientists expected the opposite, but polar bears in the Norwegian Arctic archipelago of Svalbard have become fatter and healthier since the early 1990s, all while sea ice has steadily declined due to climate change. Polar bears rely on sea ice as a platform from which to hunt the seals that they rely on for blubber-rich meals. The bears' fat reserves provide energy and insulation and allow mothers to produce rich milk for cubs.
Researchers weighed and measured 770 adults in Svalbard between 1992 and 2019 and found that bears had become significantly fatter. They think that Svalbard bears have adapted to recent ice loss by eating more land-based prey, including reindeer and walruses. The discovery, published in Scientific Reports, was particularly puzzling because of the impact of climate change in Svalbard. During the same period, global temperature rise has reduced the number of ice-free days per year in the region by almost 100 - at a rate of about four days each year.
The fatter a bear is the better it is, explained lead researcher Dr. Jon Aars from the Norwegian Polar Institute. And I would have expected to see a decline in body condition when the loss of sea ice has been so profound.
While this is unexpected good news for these Arctic predators, the researchers think it is unlikely to last. As the sea ice continues to decline, bears will have to travel further to access hunting grounds, using more energy and depleting precious fat reserves. Experts think the new findings could be linked to the population recovering from past hunting pressure. That, combined with an increase in the walrus and reindeer populations in recent decades, appears to provide the bears with a temporary boost.
Dr. John Whiteman, chief research scientist at Polar Bears International, emphasized that body condition is only one piece of the puzzle. In the long term, if ice loss continues unchecked, we know the bears will eventually disappear, he stated.
Researchers weighed and measured 770 adults in Svalbard between 1992 and 2019 and found that bears had become significantly fatter. They think that Svalbard bears have adapted to recent ice loss by eating more land-based prey, including reindeer and walruses. The discovery, published in Scientific Reports, was particularly puzzling because of the impact of climate change in Svalbard. During the same period, global temperature rise has reduced the number of ice-free days per year in the region by almost 100 - at a rate of about four days each year.
The fatter a bear is the better it is, explained lead researcher Dr. Jon Aars from the Norwegian Polar Institute. And I would have expected to see a decline in body condition when the loss of sea ice has been so profound.
While this is unexpected good news for these Arctic predators, the researchers think it is unlikely to last. As the sea ice continues to decline, bears will have to travel further to access hunting grounds, using more energy and depleting precious fat reserves. Experts think the new findings could be linked to the population recovering from past hunting pressure. That, combined with an increase in the walrus and reindeer populations in recent decades, appears to provide the bears with a temporary boost.
Dr. John Whiteman, chief research scientist at Polar Bears International, emphasized that body condition is only one piece of the puzzle. In the long term, if ice loss continues unchecked, we know the bears will eventually disappear, he stated.
