Black rail

The black rail is a widely distributed but locally occurring species in North America. It is found along the Atlantic Coast and coastal California, as well as very rarely in the north central United States. The breeding range of the Atlantic Coast race extends from Florida to Connecticut, with the northernmost breeding stronghold in southern New Jersey. Black rails winter along the Gulf Coast and the coasts of Florida, Mexico, and Central America.

In New Jersey, the black rail is a rare and local breeding species along the Atlantic and Delaware Bay coasts. Marshes along the Delaware Bay coast of Cape May, Cumberland, and Salem Counties provide a stronghold for black rails in the state. Most black rails within this area occur from Salem to Goshen and have been documented during the breeding season at Turkey Point, Greenwich Township, Fairfield Township, Dividing Creek, Heislerville Wildlife Management Area, Commercial Township, Jake’s Landing, Dennis Creek, and Goshen.

In the past three decades, black rails have been observed along the Atlantic Coast during the nesting season at Nummy Island, Marmora, Upper Township, Lester G. MacNamara Wildlife Management Area, Edwin B. Forsythe National Wildlife Refuge, and Manahawkin. Most breeding records of this species occur south of the Raritan River.

Coastal salt and brackish marshes are home to the black rail. It nests in areas of elevated marsh that are flooded only during extremely high tides. Nests are typically located in marshes dominated by salt hay. These marshes also may contain spike grass, black rush, or marsh elder. Marshes containing salt hay provide characteristically thick mats of overlapping vegetation, beneath which the rails traverse on pathways of flattened vegetation. Black rails may seek cover within vegetation in adjacent upland fields and meadows during high tides. Black rails occupy similar habitats throughout the year.

Black rails are nocturnal migrants that travel through New Jersey from September to mid-October and from mid-April to May. Although black rails typically winter in southern regions, they may rarely occur as far north as New Jersey during winter.

The black rail is an omnivorous species. It consumes aquatic invertebrates, insects, and seeds. Isopods (aquatic crustaceans), mollusks, diving beetles, weevils, earwigs, grasshoppers, ants, and spiders have been documented in their diet. These rails often forage in wet areas, gleaning food items from above and below the high-tide line. Black rails are opportunistic and thus feed largely on seasonally abundant prey, such as insects in the summer and seeds in the winter.

During the breeding season, the kee-kee-doo calls of black rails can be heard on calm nights from within salt hay marshes along the shores of the Delaware Bay. Vocal activity of black rails typically peaks during the first 2 weeks of May, although courtship and nesting dates vary depending on water levels within the marsh. One “alpha” male may dominate the chorus, while other males call less frequently. Black rails typically vocalize in the evening and throughout the night but may infrequently call during the day.

Black rail breeding colonies can be short-lived or transitory, suggesting that large areas of suitable habitat are necessary to maintain breeding populations of this species. In Maryland, territory size has been estimated at 7-9 acres.

The black rail constructs a cup nest woven of marsh grasses on the ground and concealed within mats of salt hay, spike grass, or black rush. Surrounding live grasses are intertwined into the nest structure, forming a canopy. Trampled pathways beneath tall grasses lead to and from the nest.

From late May to late June, the female lays a clutch of six to ten lightly speckled white eggs. Black rails may replace clutches that are lost to predation or flooding. Both the male and female incubate the eggs for 16 to 20 days. Although they are dependent upon their parents for food and brooding, the precocial chicks may leave the nest within a day of hatching. The age at which young gain independence is unknown.

The black rail was once considered a game bird in New Jersey. It was historically a locally common breeding species in tidal marshes along the state’s Atlantic and Delaware Bay coasts. Following the 1920s and 1930s, black rail numbers began to decline as coastal wetlands were filled, ditched, and polluted. From 1953 to 1973, nearly 25 percent of tidal marshes in New Jersey were filled or diked, with the most severe losses occurring throughout the range of the black rail in Cumberland, Salem, Cape May, Atlantic, and Ocean counties. Increased human recreational activities at coastal marshes further threatened already depressed populations of this rail. Because of this, the species was lost from many historic breeding locales, particularly along the heavily used and developed Atlantic coast.

Due to severe population declines and localized distribution resulting from habitat loss, alteration, and degradation, the black rail was listed as a threatened species in New Jersey in 1987. Because of its patchy distribution and small population size, the black rail was included as a Migratory Nongame Bird of Management Concern in the United States by the U.S. Fish and Wildlife Service in 1992. Habitat loss and population declines have also occurred in other northeastern states, such as Connecticut, New York, and Maryland. In 2012, it was reclassified in New Jersey as an endangered species.

Management for black rails must include the preservation and protection of both occupied and potential habitat. Areas of potential habitat include sites that contain suitable habitat as well as locations where black rails have previously been documented. Because they occupy breeding sites for short periods of time and have high juvenile dispersal rates, nesting black rails may be found at different locations in different years. Thus, large tracts of suitable habitat, including high marshes along the Delaware Bay shore, should be protected and considered high priority sites for this species. The protection of such locations from habitat alteration and human disturbance can also favor other endangered species such as the northern harrier (Circus cyaneus) and the short-eared owl (Asio flammeus). In addition to large tracts of coastal marsh, adjacent upland buffers should be secured to provide shelter for black rails during floods. Pesticide use should be limited or restricted at black rail sites.

Human activity must be restricted at black rail nesting sites during the breeding season. Public outreach efforts should inform birders about the disturbances created by such activities as walking through nesting habitat. In addition, the public must be must be made aware of the potential legal implications and fines for harassing endangered species. Cooperative efforts may be established in which birders can assist supervising biologists with black rail monitoring projects.

Because of the secretive nature and patchy distribution of black rails, we still have much to learn about their biology and population status. Research needs to be completed to find additional breeding sites, check existing nesting areas, and determine whether the population might be decreasing or increasing.