A perky, active bird but one that prefers to stay concealed, the marsh wren can be frustrating to birders until they learn its distinctive voice. Because this bird is secretive, listening to birds can often provide the necessary clues for proper identification when views have not been the best.

Common Name:

Marsh Wren, Long-Billed Marsh Wren

Scientific Name:

Cistothorus palustris

Scientific Family:

Troglogytidae


Appearance:

• Bill: Long, slender, dark above and pale below close to the base, slightly decurved
• Size: 5 inches long with 6-7-inch wingspan, large head, long tail
• Colors: Black, white, brown, buff, rufous
• Markings: Genders are similar with a dark brown or black cap contrasting with a thick white eyebrow and paler brown or buff cheeks. The throat is buff and the underparts range from buff or light brown to a richer rufous and may have a brown wash on the flanks. The brown back has a distinct triangle of black and white streaks. The rump is rufous or brown, and the brown wings and tail both show black barring.
  
  There is much geographic variation among these birds, with birds in western populations generally paler than their eastern cousins.
  
  Juveniles are similar to adults but overall darker and have less streaking on the back.

Foods:

Insets, snails, spiders, eggs (See: Insectivorous)

Habitat and Migration:

Marsh wrens are aptly named for their preferred habitat, and they can be found in both freshwater and brackish marshes with abundant reeds and similar vegetation, though in areas with heavier salt content, they are usually common only in winter.

These birds are neotropical migrants but do have year-round populations along the Atlantic and Gulf coasts, as well as the Pacific coast from southern British Columbia to central California. Inland, marsh wrens are present year-round in central Canada to the western regions of Oregon and Washington, southern Idaho, western Utah and throughout Nevada.

In summer, this wren's breeding range expands to include more extensive parts of central and southern Canada as well as the northern United States from the Rocky Mountains to Maine and the northeast, extending as far south as Colorado, northern Missouri and northern Pennsylvania. In winter, these birds migrate to much of the southern United States and Mexico, but they can be seen as far north as southern Utah and southern Kansas, particularly during mild winters when more marshes stay unfrozen.

Vocalizations:

Voice can be a great clue to this bird's identity, since marsh wrens are loud, active singers that will sing even at night during the breeding season. The typical song is a series of rapid gurgling trills or liquid rattles that lasts 1-3 seconds. Short buzzes or chirps may also be part of the song and there is great variation for exact song composition, but all marsh wrens use similar vocal components. Males will occasionally sing from exposed perches, offering better views than when they are foraging deep in the brush.

The typical call is a harsh "chek-chek" that can be repeated rapidly.

Behavior:

These birds are secretive and typically stay well hidden in their reedy marshes, typically low in the cover and close to the water. They are often solitary but can be seen in pairs or small groups. While foraging, they glean insects from reeds or the water's surface, and will often perch with their legs splayed between two different reeds or plant stalks. The tail is often held cocked up at a severe angle when the bird is perched, and if agitated, the bird may raise the feathers on its crown to mimic a slight crest.

Reproduction:

Marsh wrens are polygamous and a male may have multiple female mates. The male constructs several hanging globe nests of reeds and grass typically 1-15 feet above the water, but the female chooses which nest she prefers and will line it with finer grasses or feathers. Males may then roost in an unused nest.

The oval-shaped eggs are a light brown or tan color and spotted with fine flecks of a darker brown. There can be 3-10 eggs per brood, and the female parent incubates the eggs for 12-16 days. Two broods per year is common. After hatching, both parents feed the altricial young for an additional 12-16 days until the young birds are better able to forage on their own.

Attracting Marsh Wrens:

These are not typical backyard birds because they stay almost exclusively in marsh habitats that are not practical in a backyard, but they may visit a bird-friendly backyard that has a reedy area around a pond. Preserving local habitats can also encourage these birds to stay in the area, and in the field they will respond to pishing.

Conservation:

Marsh wrens are widespread and are not considered threatened or endangered, but local populations can be impacted by habitat loss, particularly when marshes or wetlands are drained for development or agriculture. Spraying marshes to control mosquitoes or other insects can also affect the food supply for marsh wrens.

Similar Birds:

• Sedge Wren (Cistothorus platensis)
• Carolina Wren (Thryothorus ludovicianus)
• Cactus Wren (Campylorhynchus bunneicapillus)

Photo – Marsh Wren © Nick Saunders