The plain-flanked rail (''Rallus wetmorei'') is an

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

species of

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

in subfamily Rallinae of family

Rallidae The rails, or Rallidae, are a large cosmopolitan family of small- to medium-sized, ground-living birds. The family exhibits considerable diversity and includes the crakes, coots, and gallinules. Many species are associated with wetlands, altho ...

, the rails, gallinules, and coots. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in ...

.HBW and BirdLife International (2021) Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip retrieved August 7, 2022

Taxonomy and systematics

The plain-flanked rail has been suggested to be

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organ ...

with the

mangrove rail The mangrove rail (''Rallus longirostris'') is a species of bird in subfamily Rallinae of family Rallidae, the rails, gallinules, and coots. It is found in Central and South America.HBW and BirdLife International (2021) Handbook of the Birds of ...

(''R. longirostris'') but this treatment has not been accepted by major taxonomic systems because the two do not interbreed where their ranges overlap. The plain-flanked rail is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 24 July 2022. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved July 24, 2022

Description

The plain-flanked rail is about long. It has a brown bill. The sexes are alike. Adults have dull gray-brown upperparts with darker centers to the feathers. They have a white loral streak on their gray-brown face and a whitish throat. Their underparts are brown with no barring.Taylor, B., P. F. D. Boesman, C. J. Sharpe, and E. de Juana (2020). Plain-flanked Rail (''Rallus wetmorei''), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.plfrai1.01 retrieved November 22, 2022

Distribution and habitat

The plain-flanked rail is known from only a few locations on the Caribbean coast of Venezuela between eastern Falcón and western Aragua states. It primarily inhabits coastal mangroves and has also been found in emergent vegetation of brackish and salwater lagoons and marshes.

Behavior

Movement

The plain-flanked rail is apparently sedentary.

Feeding

Nothing is known about the plain-flanked rail's foraging behavior or diet. Both are assumed to be similar to those of the mangrove rail, which inhabits similar landscapes. That species has a very diverse diet that includes animal prey such as crustaceans (especially crabs and crayfish), molluscs, leeches, aquatic and terrestrial insects, fish, and amphibians. It also feeds on plant matter such as seeds, berries, and tubers, especially in winter.Taylor, B. and D. A. Christie (2020). Mangrove Rail (''Rallus longirostris''), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.manrai1.01 retrieved November 22, 2022

Breeding

The plain-flanked rail's breeding season is not known in detail but includes both April and May. A few nests have been discovered; they were platforms of twigs and leaves placed on mangrove roots or in mangrove trees. Clutch sizes of four to seven eggs have been noted. Both members of a pair incubate the eggs. The incubation period and time to fledging are not known.

Vocalization

The plain-flanked rail's "advertising call" is "a series of loud, rapid 'kek-kek-kek...kek-kek-kek' notes" that are given in duet and preceded by "soft growling 'grrrrr' calls". Courting males make "a series of evenly spaced harsh 'kek' notes". The species also makes a grunting call.

Status

The IUCN originally assessed the plain-flanked rail in 1988 as Threatened; from 1994 it has been classed as Endangered. It has a very small range and an estimated population of 50 to 200 mature individuals that is believed to be decreasing. Its mangrove habitat continues to be destroyed by development for tourism and what remains is also threatened by domestic and industrial pollution.

References

{{Taxonbar, from=Q1268685 Birds of Venezuela Rallus Birds described in 1944 Taxa named by John T. Zimmer Taxonomy articles created by Polbot