Each November the town of Easton, on Maryland’s Eastern Shore, celebrates web-footed birds and their environs with its Waterfowl Festival. And each year some of the world’s best wildfowl carvers arrive with an astonishing variety of work that celebrates winged creatures. The Academy Art Museum becomes Carver’s Hall for the festival, with tables full of ducks, geese, raptors, songbirds, and owls. The high school is the place to find antique decoys as well as contemporary carvings that just…