The blackish rail (''Pardirallus nigricans'') is a 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 lightweigh ...

in the subfamily Rallinae of the rail, crake, and coot 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, althoug ...

.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 It is found in

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

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 th ...

, and possibly

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

.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. Species Lists of Birds for South American Countries and Territories. https://www.museum.lsu.edu/~Remsen/SACCCountryLists.htm retrieved July 24, 2022

Taxonomy and systematics

The blackish rail has previously been placed in the large genus ''Rallus'', and also in genus ''Orygonax'' with the

plumbeous rail The plumbeous rail (''Pardirallus sanguinolentus'') is a species of bird in the subfamily Rallinae of the rail, crake, and coot family Rallidae. It is found in Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay, Peru and Uruguay.HBW and BirdL ...

(''Pardirallus sanguinolentus''). Some authors propose that the blackish and plumbeous rails are

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 ...

, and they do form a superspecies. The blackish rail has two subspecies, the

nominate Nomination is part of the process of selecting a candidate for either election to a public office, or the bestowing of an honor or award. A collection of nominees narrowed from the full list of candidates is a short list. Political office In the ...

''P. n. nigricans'' and ''P. n. caucae''.

Description

The blackish rail is long; one male weighed . The sexes are alike. They have a long yellow-green bill and pinkish legs. The nominate subspecies has unmarked dark brown upperparts, a white chin and throat, and dark gray face and underparts. ''P. n. caucae'' is larger than the nominate and has a larger and whiter throat patch and paler underparts especially at the vent.Taylor, B. (2020). Blackish Rail (''Pardirallus nigricans''), 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.blarai1.01 retrieved October 13, 2022

Distribution and habitat

The blackish rail has a

disjunct distribution In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a s ...

. The nominate subspecies has two populations. One is found from northeastern Brazil south and west to southeastern Brazil, northern Argentina, and eastern Paraguay. The other forms a rough crescent from western Brazil through central Peru and Ecuador nearly to the border with Colombia. There are also sight records in Bolivia that lead the South American Classification Committee of the

American Ornithological Society The American Ornithological Society (AOS) is an ornithological organization based in the United States. The society was formed in October 2016 by the merger of the American Ornithologists' Union (AOU) and the Cooper Ornithological Society. Its m ...

to call it hypothetical in that country. Subspecies ''P. n. caucae'' is found in central Colombia (it is named for the

Cauca River The Cauca River () is a river in Colombia that lies between the Occidental and Central cordilleras. From its headwaters in southwestern Colombia near the city of Popayán, it joins the Magdalena River near Magangue in Bolivar Department, and th ...

). The species has been documented in western Venezuela, but whether as a member of ''P. n. caucae'' or an undescribed subspecies is not known. The blackish rail inhabits wet landscapes including marshes, heavily vegetated waterways, rice fields, wet grasslands, and lightly wooded swamps. It is mostly a bird of the lowlands but in the Andes is found between and there is one record in Peru at about .

Behavior

Movement

No movement by the blackish rail has been documented except for the

vagrant Vagrancy is the condition of homelessness without regular employment or income. Vagrants (also known as bums, vagabonds, rogues, tramps or drifters) usually live in poverty and support themselves by begging, scavenging, petty theft, temporar ...

in Peru.

Feeding

The blackish rail usually forages in cover but occasionally in the open at the edges of vegetation or in small clear areas. Its diet is not known but is assumed to be insects and other invertebrates. There is one record of an individual "venturing 5m into restaurant garden for food scraps."

Breeding

The blackish rail's breeding season has not been determined. One nest of either the blackish or plumbeous rail was a cup placed among shoots on a stump in a swamp. The clutch size is two or three and the incubation time (in captivity) is 18 to 21 days. The black downy chicks leave the nest soon after they hatch, and both parents care for the chicks.

Vocalization

The blackish rail has a large vocal repertoire. What is thought to be a male song is a "very sharp, loud, penetrating, repeated 'whuueeee' or 'wheee'." Other vocalizations have been described as a "very fast, metallic 'tii'd'dit'", a "complaining 'keeeeaaa'", a "rapid, repeated 'chchchee'" and a "sharp double squeak".

Status

The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed the blackish rail as being of Least Concern. It has a very large range and an estimated population of up to 67,000 mature individuals. The population trend is unknown. No immediate threats have been identified. It is regarded as locally common in a few areas but generally as patchy and uncommon. Its "status sdifficult to assess, as hespecies susually secretive and difficult to observe."

References

{{Taxonbar, from=Q960214 blackish rail Birds of South America Birds of Colombia Birds of Venezuela Birds of the Amazon Basin Birds of the Ecuadorian Amazon Birds of the Peruvian Amazon Birds of the Bolivian Amazon Birds of Brazil Birds of Paraguay blackish rail Taxa named by Louis Jean Pierre Vieillot Taxonomy articles created by Polbot