The Marsh Wren (Cistothorus palustris) is a small, formally common, North American songbird inhabiting cattail marshes whose numbers have declined with the loss of suitable wetland habitat. Draining of marshes leads to its local extinction.
These birds forage actively in vegetation, sometimes flying up to catch insects in flight. They mainly eat insects, but may also consume spiders and snails. The Marsh Wren sings all day and throughout the night producing a gurgling, rattling trill often used to declare ownership of its territory.
The nest is an oval lump of woven wet grass, cattails, and rushes, which is lined with fine grass, plant down, and feathers. It is attached to marsh vegetation and entered from the side. Industrious male Marsh Wrens build "dummy nests" in their nesting territories, occasionally up to twenty or more, although most are never used for raising young.
Normally four to six eggs are laid twice each year, although the number can range from three to ten. The eggs are generally pale brown and heavily dotted with dark brown; although sometimes they may be all white. Only the female incubates the eggs which hatch after 13-16 days. The young leave the nest about 12-16 days after hatching.