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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, and similarly rapid declines are expected throughout its full range. The declines are assumed to continue into the future as an increased frequency of extreme precipitation events and flooding are projected to severely damage and destroy its 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 this species has not been quantified directly and a distinct paucity of data renders the calculation of reliable estimates difficult. The subspecies jamaicensis, which occurs in eastern North and Central America as well as in the Caribbean, was estimated in the year 2000 to number 25,000-100,000 individuals, roughly equating to 15,000-70,000 mature individuals (Wetlands International 2020). However, given the dramatic declines witnessed in this subspecies in the years since, it would appear that this figure is a considerable overestimate. Watts (2016) recently provided an accurate estimate for the population of jamaicensis residing on the USA's eastern coast between New England and Florida, 455-1,315 breeding pairs or 910-2,630 mature individuals, however this population does not incorporate those individuals that comprise the Texan, central USA, Caribbean or Brazilian individuals of the same subspecies. No other population estimates are thought to be currently available for jamaicensis. The subspecies coturniculus, 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 2020). There are no estimates available for the subspecies murivagans and salinasi in western South America (Wetlands International 2020). As a result, the global population is tentatively placed in the band 10,000-49,999 mature individuals however, such estimates require confirmation and are liable to change should more accurate estimates be provided.

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 a ten year period and it is precautionarily assumed that subspecies jamaicensis is declining at this rate throughout its entire range.
The other three subspecies coturniculus, murivagans, and salinasi inhabit similar habitats and are likely faced with the same threats posed to jamaicensis, particularly those associated with climate change, and are therefore assumed to be undergoing declines at a similar rate. The rate of population decline for the global population is therefore tentatively placed in the band 50-79% across a ten year period, although further detailed population assessments are required to confirm this trend.

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 (Roach and Barrett 2015, Watts 2016). Coastal habitat may be influenced by tides (USFWS 2018a). An important characteristic of sites occupied by the species is typically tall, dense herbaceous vegetation, which it uses for shelter (USFWS 2018a). It occupies sites with shallower water than other rallids (Roach 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 builds its nests low to the ground in areas of dense vegetation with water depths 1-6 cm (Watts 2016, USFWS 2018a). It feeds on terrestrial and aquatic invertebrates (Roach and Barrett 2015). The species is secretive in behaviour, moving mainly by walking and 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), particularly along the west coast where up to 85% of estuarine vegetated tidal wetlands have been lost (Brophy et al. 2019). 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 inundation of coastal marsh habitat from rising sea levels 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 projects including the Lower Colorado River Multi-species Habitat Conservation Program and South Bay Salt Ponds Restoration Project (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 to aid in the protection of subspecies jamaicensis. A recovery plan for this subspecies is also being developed (USFWS 2019) and jamaicensis was proposed for listing under the Endangered Species Act in the U.S.A. in October 2018. The Atlantic Coast Joint Venture (ACJV) have recently developed objectives to stabilise, and then increase populations of jamaicensis throughout the Atlantic coast states, USA (ACJV 2020).

Conservation Actions Proposed

Assess the population size, particularly of the subspecies jamaicensis in unassessed regions, and 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 (Roach and Barrett 2015), possibly through the use of water control structures to maintain appropriate water depth and dredge spoil to provide higher nesting sites (ACJV 2020). Control invasive plants and woody encroachment, possibly through prescribed fire (ACJV 2020). Protect threatened subpopulations.

Acknowledgements

Text account compilers
Everest, J., Hermes, C.

Contributors
Benstead, P., Bird, J., Elphick, C., Gallardo, R., Hand, C., Isherwood, I., Lees, A., Nadeau, C., Roach, N., Sharpe, C.J., Tsao, D., Wege, D. & Wheatley, H.


Recommended citation
BirdLife International (2022) Species factsheet: Laterallus jamaicensis. Downloaded from http://www.birdlife.org on 25/09/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/09/2022.