Male marsh wrens (Cistothorus palustris), those denizens of marshes and shallow water, build globes of woven rushes, marsh grasses, cattails and other vegetation sometimes intermixed with mud and attached to cattails, rushes or flags safely above the water level. Each of these nests has a small entrance hole on one side.
Each male builds up to as many as twenty “dummy nests” in his territory, most of which are never used for raising young, although adults may sleep in them outside of the breeding season. One male may have two or more mates. The female chooses one of the nests and lines it with fine grass, plant down and feathers.
The 4 or 5 eggs (sometimes 3 or 6) are pale brown heavily dotted with dark brown or the eggs may be all white. The female does most of the incubating. The eggs hatch after 13 to 16 days. Both parents feed the young, although the female probably assumes more responsibility for the nest since the male usually has more than one “family” to feed and defend. The young leave the nest about 12 to 16 days after hatching. A marsh wren female usually has two broods per season and sometimes a third.
This marsh wren and the nests were photographed in Ash Creek Wildlife Area (Modoc and Lassen Counties CA)
More information on this exuberant singer can be found in my earlier posts: “Marsh Wren” on 11-22-11 and “Not Cute Anymore. . .” on 03-13-12.