From a helicopter, it can be hard to spot a polar bear against the frozen tundra. So when the polar bear biologist Jon Aars heads out for his annual research trips, he scans the landscape for flashes of movement or subtle variations in color — the slightly yellowish hue of the bears’ fur set off against the white snow.
“Also, very often, you see the footprints before you see the bear,” Dr. Aars said. “And the bear is usually where the footprints stop.”
Dr. Aars is one in a long line of polar bear researchers at the Norwegian Polar Institute,