A population of bears in Norway’s Arctic is confounding scientists’ expectations, getting fatter and healthier even as the sea ice melts rapidly.

Adult polar bears around Norway's Svalbard archipelago have become fatter on average over the past two decades even as Arctic sea ice has shrunk, according to a new study.

To Aars’s surprise, the polar bears were in “fairly good” condition, even recovering from a drop in BCI from the 1990s to 2000—the opposite of what he and his team had anticipated.