We'll be looking for the many waterfowl and shorebirds that come to spend the winter at North County's coastal wetlands. FYI: The location of this walk alternates every month between Lower Crest Canyon and San Andres Drive.    Directions for Lower Crest Canyon— From I-5, take Via de la Valle west; left on Jimmy Durante Blvd.; left on San Dieguito Rd. Drive east 1 mile to trailhead. (January, March, May, September, November.)   Directions for San Andres Drive— From I-5,…