This is another elusive marsh will-o'-the-wisp, far more often heard than seen altho its call "did-u-thunk" is so thin that even it may escape notice.
Wayne says the females' notes are "croo-croo-croo-o" and the males' quite different — "kuk-kuk-kuk-kuk." Clark spent a whole day trying to catch a bird on its nest, visiting the home every half hour, without even a quiver of surrounding sedge to show which way the feathered Houdini went.
NEST: of dried sedge, about six inches across, well concealed in green or dead grass in marshy ground.
EGGS: 6–10; buff or pink-white, evenly spotted with chestnut and pale brown.
Eastern United States; west to Kansas and Texas coast.