After wearing out its welcome over several days, last week’s never-ending Nor’easter finally passed, leaving a handful of smiling birders in its wake. Why are they smiling? Are they storm-damage sadists who are really into coastal erosion? Maybe, but many birders welcome a good Nor’easter, or, as you weather nerds may call them, macro-scale extratropical cyclones. That’s because these storms often come bearing gifts. The initial strong northeast winds can load up Cape Cod Bay with all manner of