National Geographic: 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 …