Sedge wren

The sedge wren breeds in eastern North America from southern Canada to Virginia and west to Kansas, Missouri, and Indiana. They also occur from southern Mexico to southern South America. Sedge wrens that breed in North America winter along the Gulf and Atlantic coasts, mainly south of Maryland.

Sedge wrens can be found in wet meadows, freshwater marshes, bogs, and the higher portions of salt or brackish coastal marshes throughout the year. Sedge wrens favor marshes containing sedges, grasses, rushes, scattered shrubs, and other emergent vegetation.

Sedge wrens typically exhibit low fidelity to breeding sites each year. Or they are not likely to return to the same nest site, year after year. This could be due to changes in water levels or vegetative structure and composition. Because they are sensitive to hydrology, sedge wrens may avoid nesting in areas that are too wet or too dry. They may abandon sites if shrubby growth dominates grasses due to vegetative succession.

The sedge wren’s diet is dominated by insects and spiders. They also eat beetles, weevils, moths, caterpillars, ants, grasshoppers, crickets, locusts, flies, and mosquitoes. They forage on the ground or glean insects from vegetation.

In late May, in their nesting habitat males sing to attract mates and defend his territory. He constructs several nests. They use only one nest. The rest are built to confuse would-be predators or for roosting at night. Nests are constructed of woven grasses and sedges that form a ball. There is only one opening on the side. The nest is concealed among the surrounding vegetation and is placed low above the ground. Sometimes water sits directly below the nest. The female selects the nest site and lines it with thin grasses, hair, and feathers.

The female lays between 6 to 7 white eggs. They are incubated for 12 to 14 days until they hatch. The female cares for the young once they hatch, and the male provides most of the food. After only 14 days from when the young hatched, the young fledge or fly for the first time. Females can lay another clutch of eggs. If the female lays another clutch the male cares for the juveniles or fledglings. Fledglings remain together until they migrate south in the fall.

In the early 1900’s, the sedge wren was a locally distributed breeding species in New Jersey. Since the 1950’s, bird surveys have revealed alarming declines of this species in the Northeast. The draining and filling of wetlands, ditching of salt marshes, and the spread of phragmites (Phragmites australis) have all resulted in severe habitat loss for the sedge wren. Habitat loss has been the leading cause for declines in the sedge wren population. Wet sedge or grass meadows, the habitat types required by sedge wrens, are among the most frequently destroyed wetlands in the United States.

Due to these factors, the sedge wren was listed as a threatened species in New Jersey in 1979. By the early 1980’s, it was not known if any breeding sedge wrens remained in New Jersey. Due to its dire situation, the sedge wren was reclassified as an endangered species in New Jersey in 1984. The sedge wren has been listed as a Migratory Nongame Bird of Management Concern by the U.S. Fish and Wildlife Service since 1992.

Currently, the sedge wren is a very rare breeding species in New Jersey. It is doubtful that this species’ population will ever return to its historic numbers. Because it occurs in small, isolated populations, it may take a long time for it to recover. Sedge wrens have suffered severe declines throughout much of the northeastern United States and are consequently listed as endangered (Maine, New Hampshire, Massachusetts, and Connecticut), threatened (Vermont, Pennsylvania, Maryland, and Virginia), or of special concern (New York).