Five minutes past midnight in Svalbard: The wild world is awake and clattering. At the edge of a sheltered estuary in the Adventdalen, a valley on a cluster of islands halfway between Norway and the North Pole, a flock of arctic terns soar and wheel in the perpetual daylight. They're agitated. A pair of glaucous gulls--chick snatchers, egg stealers, the Arctic's formidable winged predators--are approaching from the east. The terns put up a fierce defense. They flash their red beaks at the gulls and turn themselves into a cloud of sharpness.
The gambit works. The gulls bypass the terns and circle inland, passing over a pair of ground-nesting eiders, a kennel of sled dogs, and a solitary reindeer feeding on the tundra.
It's a typical summer night in Svalbard, an entirely atypical refuge in the high Arctic that abounds with an extraordinary array of wildlife. Few places in the circumpolar region can match its biodensity. Polar bears thrive here. Roughly half ...