Over the decades, these research trips have shed light on the basic biology and ecology of the bears and, in recent years, helped scientists keep tabs on how the animals are coping with climate change. The rapid habitat changes are already their behavior; with the sea ice retreating quickly, some of the bears now have to swim long distances in order to find places to den. But so far, the bears themselves still seem robust, Dr. Aars said.
If that begins to change, however, as researchers worry that it will, these annual field trips will help uncover problems early.
Here’s how scientists pull them off.
