Melting Ice, Fatter Bears: Study Finds Unexpected Polar Bear Trend

Polar bears in the Arctic are defying expectations. A new long-term study tracking adult polar bears around Norway’s Svalbard archipelago has found that the animals have become heavier over the past two decades — even as sea ice in the region has declined sharply.

Researchers analyzed nearly 1,200 body measurements collected from adult polar bears between 1992 and 2019. Over that period, the Barents Sea experienced around 100 additional ice-free days, a dramatic shift driven by climate change.

Yet instead of showing signs of decline, the average body condition of adult bears improved after 2000, indicating higher fat reserves.

Scientists say the findings challenge the assumption that shrinking sea ice will immediately lead to poorer health across all polar bear populations. The researchers suggest several possible explanations, including changes in available food sources.

As sea ice retreats, prey such as ringed seals may become more concentrated in smaller ice areas, making hunting more efficient. Increased access to land-based prey, like reindeer and walrus, may also be playing a role.

Fat reserves are critical for polar bears, particularly for females, who need sufficient body weight to reproduce and survive the harsh Arctic winter. However, researchers caution that this positive trend may not last.

Continued ice loss could eventually force bears to travel farther to hunt, increasing energy costs and pushing populations past a critical threshold.