The bear had buried its face in trash. Then two ears flicked up, and it raised its head and took a few steps back. It moved with languor – I would have expected it to lumber and thud, but its steps were eminently controlled. I could see the machinery of its muscles and bones working beneath its fitted coat. It swung its head to one side and back before resuming its meal.
Polar bears are aquatic animals: Their paws are webbed for swimming and their necks highly extendable for breathing in rough seas; a whalelike layer of blubber makes them buoyant and impervious to cold – they're so well-insulated, they're nearly invisible in infrared photographs. They can swim more than 200 miles, run 25 miles per hour, walk on thinner ice than seems possible because their paws splay wildly to distribute their weight. They can smell a 150-pound seal under three feet of ice from a mile away, approach its breathing hole soundlessly, and casually pull it from the sea. They will reach into ice floe threads to grab 3,000-pound beluga whales. As the whales spin to get away, the bears' claws dig spiral gashes into their bodies, a design that may impress whale hunters years later.
Encounters between humans and polar bears are infrequent, and fatal attacks remain exceedingly rare. But polar bears are superb and opportunistic hunters, and if they're hungry enough, they will kill and eat humans. Unlike brown bears, which usually attack only when they're startled, and will often maul a victim and leave, polar bears are predatory. They are stealth hunters: You won't see or hear them until they charge.
I made out two more bears, absorbed in eating, before the whine-roar of an approaching snowmobile caused them to scurry away like deer and disappear behind the piles.