The Marsh Wren (Cistothorus palustris) is a small North American songbird of the wren family. It is sometimes called Long-billed Marsh Wren to distinguish it from the Sedge Wren, also known as Short-billed Marsh Wren. Adults have brown upperparts with a light brown belly and flanks and a white throat and breast. The back is black with white stripes. They have a dark cap with a white line over the eyes and a short thin bill.