Polar bears in Svalbard are getting fatter. Since the early 1990s, as sea ice has steadily vanished from the Norwegian Arctic, the bears have somehow become heavier and healthier — the opposite of what climate scientists expected.
Researchers weighed and measured 770 adult polar bears between 1992 and 2019 and found a clear trend: these animals were packing on weight. The mechanism is straightforward but surprising. Polar bears hunt seals on sea ice, and seal blubber is their primary fuel — it's what keeps them warm, energized, and able to produce rich milk for cubs. As ice disappears, that hunting platform should vanish with it. Yet in Svalbard, something else has shifted.
The Unexpected Buffet
Walruses have made a comeback. Once hunted to near extinction, they've been protected in Norway since the 1950s, and their numbers have grown steadily. For a polar bear, a walrus is essentially a floating feast — far more calories than a seal. The bears have also begun hunting reindeer on land, a food source they rarely accessed before. "There are a lot more walruses around for them to hunt these days," said Dr. Jon Aars, lead researcher at the Norwegian Polar Institute. "It is also possible that they are able to hunt seals more efficiently" as the remaining seals crowd into smaller patches of ice, making them easier to catch.
We're a new kind of news feed.
Regular news is designed to drain you. We're a non-profit built to restore you. Every story we publish is scored for impact, progress, and hope.
Start Your News DetoxThis is genuinely remarkable: a large predator adapting to a radically altered environment, not by evolving, but by shifting what it eats. The bears in Svalbard are proof that ecosystems can be more flexible than we assume. The recovery also reflects something else working — strict hunting protections put in place decades ago meant the bear population itself was healthier going into this period of change, better positioned to adapt.
But here's the catch, and it matters. Experts are clear this is a temporary reprieve. As sea ice continues to shrink, polar bears will have to travel farther to reach walruses and seals. That extra travel burns energy, depleting the fat reserves they've built up. Recent research on the same population shows that more ice-free days are already linked to lower cub survival rates. The current abundance of alternative food is masking a deeper problem: the system they depend on is fundamentally breaking down.
What's happening in Svalbard right now is adaptation under pressure, not a solution. It's a window into how wildlife responds when pushed to the edge — sometimes with surprising resilience, but always with limits. As ice loss accelerates, those limits will matter.
