AVIAN VISTA: Birders train their sights Friday morning on the far side of the reservoir at MacArthur Boulevard and Reservoir Road, seeking an unusual glimpse of migrating shorebirds. A variety of sandpipers and plovers were taking a rain delay on their way from points in South America to Canada, drawn by the patch of sediment exposed by the low water in the reservoir, said Andrés Anchondo, a director of the D.C. Audubon Society. “You have to be really lucky to see them,” Anchondo said. Birds: Glover Archbold National Park