In brief
In a surprising twist amid ongoing climate change, polar bears in Norway's Svalbard region have shown improved health, gaining weight and becoming healthier since the early 1990s. Researchers discovered that these bears have adapted to declining sea ice by hunting more effectively on land, particularly targeting reindeer and walruses, which have recovered from previous hunting pressures. However, experts caution that this trend might not be sustainable as ongoing climate stresses could ultimately threaten their existence.
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.Walruses have been officially protected in Norway since the 1950s, after being hunted to near extinction. This protection has boosted their numbers, providing a new source of food for polar bears.As sea ice continues to decline, experts warn that bears will have to travel further to access hunting grounds, using more energy and depleting fat reserves. While these findings are positive short-term, the long-term outlook for polar bears remains concerning, as they are ultimately dependent on sea ice for survival.
