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Black Rail Laterallus jamaicensis



Justification

Justification of Red List Category
This species has been undergoing rapid declines in parts of its range in North America due to the loss and degradation of its habitat. The declines are assumed to go on, as an increased frequency of extreme precipitation events and flooding are projected to severely damage and destroy the habitat. At least in parts of the range, there is a high probability that the species may be extirpated by 2068. It is therefore listed as Endangered.

Population justification
The global population size of the species has not been quantified directly. The subspecies jamaicensis, which occurs in eastern North and Central America as well as in the Caribbean, is estimated at 25,000-100,000 individuals, roughly equating to 15,000-70,000 mature individuals (Wetlands International 2019). The subspecies cortinuculus, which occurs in California and northern Mexico, is estimated at 10,000-25,000 individuals, roughly equating to 7,000-17,000 mature individuals (Wetlands International 2019). There are no estimates available for the subspecies murivagans and salinasi in western South America (Wetlands International 2019). Tentatively, the population is here placed in the band 28,000-92,000 mature individuals, but this requires confirmation.

Trend justification
This species is facing a number of serious threats which are thought to be causing declines in many parts of its range. The number of recent records suggest it is extremely scarce or no longer occurs in a number of former areas. A recent projection of the future resilience of the subspecies jamaicensis in the eastern U.S.A. based on survey data of known populations used different scenarios of sea level rise, land management and the combined effects of both; it shows that the species is undergoing a steep decline and that there is a high probability that the species will be extirpated in the area by 2068 (USFWS 2018a). The surveys give evidence of a population decline at 90% along the east coast of the country since the early 1990s (USFWS 2018b), which is projected to continue. This decline equates to a rate of c. 60-69% over three generations. It is precautionarily assumed that subspecies jamaicensis is declining at this rate throughout its entire range; indicating that 15,000-70,000 mature individuals decline at 60-69% over three generations. Unless further information becomes available, the remaining 12,000-25,000 mature individuals are assumed to decline moderately rapidly at 20-29% over three generations. This means that the global population would be declining at a rate of roughly 50-60% over three generations. It cannot be ruled out, though, that the three subspecies coturniculus, murivagans and salinasi are declining at a rate similar to jamaicensis; if this were to confirmed, the overall rate of decline may have to be revised upwards.

Distribution and population

Laterallus jamaicensis is widespread, but very local and rare, in fresh and saline marshes, wet meadows and savanna in North, Central and South America and in the Caribbean. The nominate subspecies jamaicensis occurs on the east coast of U.S.A., with sporadic records inland to Colorado and Minnesota (but no confirmed nesting since 1932). It is very local in north-east Mexico, Belize, Costa Rica, Panama (only in 1963), and has recently been recorded in Honduras (R. Gallardo in litt. 2013). The species is possibly breeding in Guatemala, where it may have been overlooked in the past decades (Eisermann and Avendano 2018). It is locally rare in the Dominican Republic and Haiti, but mainly a winter visitor in Jamaica and Cuba. It has probably been extirpated as a breeder from Puerto Rico (to U.S.A.) by introduced mongooses, and is now extremely rare in winter. It is recorded as a non-breeder in the Virgin Islands (to U.S.A.). There are few records from northern Brazil (Lees et al. 2014). The subspecies coturniculus is very local in south-west USA, irregularly to north-west Mexico (one recent record). The race murivagans occurs at few coastal marshes in central Peru. The race salinasi is rare and local in south Peru to central Chile and adjacent parts of west-central Argentina. It may occur in the Colombian East Andes. In USA, most populations declined drastically in the 20th century and the breeding range has seriously contracted.

Ecology

The species inhabits saline, brackish and freshwater marsh habitats. It can be found in wet meadows and savanna, coastal prairies and even impoundment areas like sewage treatment plants (Nicolette and Barret 2015, Watts 2016). Coastal habitat may be influenced by tides (USFWS 2018a). An important characteristic of sites occupied by the species is tall, dense herbaceous vegetation, which it uses for shelter (USFWS 2018a). It occupies sites with shallower water than other rallids (Nicolette and Barrett 2015), but particularly juveniles require elevated refugia to retreat to in case of a rise in water level (USFWS 2018a). Particular during the breeding season, the species has strict habitat requirements, as it places its nests only in water of 1-6 cm depth (Watts 2016, USFWS 2018a). It feeds on terrestrial and aquatic invertebrates (Nicolette and Barrett 2015). The species is secretive in behaviour, moving mainly by running through dense vegetation; flights are short and rare (Taylor and van Perlo 1998, USFWS 2018a).

Threats

The major threat to the species is the loss of its habitat. Wetlands are degraded due to pollution, wildfires and grazing (Eddleman et al. 1994, Taylor and van Perlo 1998). About 50% of the original wetlands in the U.S.A. have been lost since European settlement in the 19th century (USFWS 2018a). The most severe causes for concern are changes in the water level, as the species has strict requirements for a specific water depth of < 6 cm for nesting. Within the range of the Black Rail in the U.S.A., wetlands are being drained and ditched as groundwater is abstracted for agricultural expansion and urban development (Eddleman et al. 1994, USFWS 2018a). Climate change is projected to massively impact on the hydrologic regimes of wetlands in various ways: increasing temperatures may lead to a drying up of wetlands, an encroachment of mangrove forests into coastal marshes and to range expansions of non-native species (USFWS 2018a and references therein). On the other hand, an increased frequency of extreme weather events with extreme precipitation, hurricanes and increased flooding and inundations can cause massive damage to the habitat, destroy the vegetation cover and cause direct mortality when the water level rises (USFWS 2018a). Modelling future resiliency of the species in the eastern U.S.A. revealed that under different climate change and land management scenarios the species will undergo a steep decline in the future, until a complete extirpation from the area by 2068 (USFWS 2018a).

Conservation actions

Conservation Actions Underway

The species occurs in a number of protected areas. Habitat restoration and creation for coturniculus is ongoing as part of the Lower Colorado River Multi-species Habitat Conservation Program (LCRMSCP 2004, Nadeau and Conway 2015). The species is included in the North American Marsh Bird Monitoring Protocol (Conway 2011). South Carolina Department of Natural Resources has implemented a monitoring program. A Black Rail Working Group has been established. A recovery plan for the subspecies jamaicensis is being developed (USFWS 2019). The species is proposed for listing under the Endangered Species Act in the U.S.A.

Conservation Actions Proposed

Assess the population size, particularly of the subspecies murivagans and salinasi in western South America. Monitor the population trend. Monitor the availability and quality of habitat. Conserve wetland habitats within its range. Manage retreat at coastal sites so they continue to support the species in the face of sea level rise and increased storm frequency. Take the species's needs into account when managing potentially suitable impounded tidal marshes. Protect threatened subpopulations.

Acknowledgements

Text account compilers
Sharpe, C.J., Wege, D., Wheatley, H., Hermes, C., Benstead, P., Bird, J., Isherwood, I.

Contributors
Elphick, C., Gallardo, R., Hand, C., Lees, A., Nadeau, C., Roach, N. & Tsao, D.


Recommended citation
BirdLife International (2020) Species factsheet: Laterallus jamaicensis. Downloaded from http://www.birdlife.org on 19/02/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/02/2020.