Arctic sea ice is vanishing faster than ever, and scientists expected polar bears in Svalbard would grow thinner. Their icy hunting grounds are rapidly shrinking, but polar bears in Norway's remote Svalbard archipelago have defied the odds by bulking up instead of wasting away, a study said Thursday. But instead of growing leaner like polar bears in other parts of the Arctic where the sea ice where they hunt is retreating, those in Svalbard have gained body fat. Warmer temperatures have also made it easier for them to hunt ringed seals that now crowd in smaller sea ice areas. They found that their BCI fell until 2000 but increased in subsequent years despite a period of rapid loss of sea ice.