The channel between Staten Island and New Jersey meanders past smokestacks, oil tanks and towering cargo cranes, an industrial landscape that overshadows the occasional stretch of marsh or woodlands. It was this gritty waterfront that provided the background for one of nature's stunning revivals, starting in the mid-1970s: the return of herons to New York Harbor. It started when a longshoreman spotted some of the graceful birds wading near islands in the harbor. By the late 1980s, New York Harbor had become home to one of the largest heron rookeries in the Northeast, with several thousand birds nesting on the...