State Status: Endangered
Federal Status: Threatened
Description
The smallest of North America's rail species at six inches in length; the black rail is stocky, short-billed, short-tailed, and round-winged. It is mostly dark gray or black on the head, bill, and chest with white-speckled dark wings, back and lower abdomen. The throat of the female is pale gray or white, while the throat of the male is pale to medium gray. The nape and upper back is chestnut-brown and the eyes are scarlet red. Their breeding season call is a three-noted "kickee-doo" or "kic-kic-ker." Immature black rails are similar in appearance to the adults but with less distinct spotting and streaking on the body. Another feature in juvenile black rails are the eyes which are amber to hazel until they turn red at three months old.
Life History
The extent of migration in this species is poorly understood. Individuals have been recorded in winter as far north as New Jersey; however, it is likely that most east coast populations migrate south. Spring migration occurs from mid-March to May. Peak nesting occurs from June to mid-July. The nest is concealed in grasses and is woven together with live and dead vegetation. It has a deep cup shape with a canopy over top with an entrance ramp leading up the side. A clutch of 6 to 10 buffy white eggs with brown spots is incubated for 16 to 20 days. Both sexes share incubation and brood rearing duties suggesting a monogamous relationship, but it is unknown whether the pair bond lasts longer than one breeding season. Chicks are hatched one at a time and are semiprecocial (born at a semi-advanced state). The degree of parental care and chick survival is unknown. Fall migration occurs in September to mid-October.
Distribution and Habitat
Black rails breed locally in California, Kansas, and along the Atlantic coast from southern New England to the Gulf coast states. They winter from the southern Atlantic coast, south to Central America. Historically, the breeding range may have extended as far north as Massachusetts but today the core breeding range is from New Jersey south along the coast to Florida. In the late 1930s, breeding locations in New York were limited to just a few sites on Long Island's south shore (Oak Beach marsh, Long Beach and Lido Beach). However, from the 1940s to 1968 no breeding activity was recorded at these sites or anywhere else in the state. In 1968, black rails were once again confirmed breeding at Oak Beach marsh with the discovery of two nesting pair. During the 2nd New York State Breeding Bird Atlas (2000-2005), a single bird was heard calling from the marsh.
Black rails nest on the higher ground portions of coastal salt and brackish marshes dominated by rushes, grasses, and sedges. They have also been documented less frequently in wet meadows and freshwater emergent marshes. The single remaining breeding location in New York is dominated by saltmeadow cordgrass and spikegrass interspersed with shallow pools of water.
Status
The black rail population has been declining in the eastern United States for over a century and some reports suggest that the population may have decreased by as much as 75% in just the last 10-20 years. It has likely been extirpated from the northern extent of its range in Connecticut and Massachusetts and the number of nesting locations and individuals within its core range has decreased to very low numbers.
Population declines are likely attributable to increasing development in coastal areas that has resulted in habitat loss and degradation of breeding areas. Black rails build nests in the high ground areas of coastal marshes because they are less prone to flooding than lower-lying areas; however, those characteristics also make it ideal for residential and commercial development. In addition, many remaining salt marshes are in close proximity to development and are subject to many factors that reduce habitat quality:
- In an effort to control mosquito populations drain water is often ditched. This management practice also reduces the abundance and diversity of other invertebrates, which are the black rail's food base.
- Predators, such as raccoons, cats, and rats, occur at higher densities near human development than in wild areas. Due to their high-marsh habitat, black rails may be more prone to mammalian nest predation than more interior-marsh nesting species.
- Soil is often contaminated with PCBs, heavy metals and pesticides. Birds that feed on prey from contaminated soil may have lower reproductive success and higher mortality than birds in less polluted wetlands.
- Invasive species, such as Phragmites, often crowd out native vegetation and form dense monoculture stands. The diversity of wildlife is drastically reduced at sites once taken over by Phragmites. It is unlikely that black rails can utilize marshes dominated by Phragmites and these stands represent a further loss of black rail habitat.
Management and Research Needs
The future of the black rail is uncertain. Despite very low population numbers, the black rail is not protected by federal listing as threatened or endangered. It is also unprotected in many of the states within its southern range; however, it is listed as endangered in most of the Mid-Atlantic states. The biggest threat may be yet to come if sea levels rise as a result of climate change. Climate change model predictions suggest that the low-lying habitat of this species will likely be among the first areas inundated.
Little is known about black rails, due to its secretive nature and rareness. Additional research on this species is needed in all areas of biology. Current research along the east coast is focusing on assessing the black rail population and developing a conservation action plan aimed at increasing the population throughout its range.