"A fat bear is a healthy bear," Jon Aars, a senior scientist with the Norwegian Polar Institute, told CBS News on Thursday. He's been tracking polar bears on the remote, Arctic Norwegian archipelago of Svalbard for more than 20 years. The head of the Polar Bear Program at the Norwegian Polar Institute (left), and Norwegian veterinarian Rolf Arne Olberg (right) measure a male polar bear in eastern Spitzbergen, in the Svalbard archipelago, in an April 17, 2025 file photo. OLIVIER MORIN/AFP/Getty"I was quite surprised," Aars admitted, "because we have lost so much sea ice since I started." A view of a polar bear during the 5th National Arctic Scientific Research Expedition in Svalbard, Norway, July 16, 2025.