We often think of butterflies as fleeting beauties, and indeed many species have brief flight periods. But Question Marks (Polygonia interrogationis) are different in that adults can fly late in the year, overwinter as adults, and emerge in the spring to fly again.
Notice the white markings, on the underside of the hind wing, which form a ? and separate this creature from the related Eastern Comma (P. comma), who, as you might expect, has a single, comma-shaped mark. I photographed this butterfly along the coast in Biddeford, ME on 8/31/14.