The Aztec rail or Mexican rail, (''Rallus tenuirostris'') is a

Near Threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

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 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, althoug ...

, the rails, gallinules, and coots.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

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 elsew ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Taxonomy and systematics

The Aztec rail was previously treated as

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 what are now 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''),

Ridgway's rail Ridgway's rail (''Rallus obsoletus'') is a near-threatened species of bird. It is found principally in California's San Francisco Bay to southern Baja California. A member of the rail family, Rallidae, it is a chicken-sized bird that rarely flie ...

(''R. obsoletus''), the

king rail The king rail (''Rallus elegans'') is a waterbird, the largest North American rail. Description Distinct features are a long bill with a slight downward curve, with adults being brown on the back and rusty-brown on the face and breast with a da ...

(''R. elegans''), and the

clapper rail The clapper rail (''Rallus crepitans'') is a member of the rail family, Rallidae. The taxonomy for this species is confusing and still being determined. It is a large brown rail that is resident in wetlands along the Atlantic coasts of the easte ...

(''R. crepitans''), and more recently as conspecific with the king rail. Worldwide taxonomic systems now agree that each of the five is a separate species based on a 2013 study that described their different genetics and morphologies.Clements, J. F., T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2022. The eBird/Clements checklist of birds of the world: v2022. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved November 10, 2022 Many systems treat it as most closely related to Ridgway's rail.del Hoyo, J., N. Collar, and D. A. Christie (2020). Aztec Rail (''Rallus tenuirostris''), 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.kinrai2.01 retrieved November 22, 2022 The Aztec 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 ...

Description

The Aztec rail is long. Males weigh and females . The sexes have similar plumage. The species has dark and light morphs. The dark morph has rich brown upperparts with blackish markings on the back. It has a pale pinkish cheek stripe and a white chin and throat. Its underparts are rufous with dull brown and white to pinkish cinnamon barring on the flanks and white undertail

coverts A covert feather or tectrix on a bird is one of a set of feathers, called coverts (or ''tectrices''), which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail. Ear coverts The ear coverts are sm ...

. The light morph's underparts have a pale white center with a pinkish cinnamon wash. Juveniles have duller and darker upperparts and paler underparts than adults.

Distribution and habitat

The Aztec rail is found only in central Mexico. It inhabits both seasonal and permanent highland freshwater marshes. In elevation it ranges from up to at least .

Behavior

Movement

The Aztec rail is mostly a year-round resident throughout its range but some apparently disperse from permanent wetlands to temporary ones during the May to September rainy season.

Feeding

The Aztec rail's principal food is crustaceans, especially crayfish, but its diet also includes molluscs, terrestrial and aquatic insects, and possibly spiders, fish, and amphibians.

Breeding

The Aztec rail's core breeding season extends from May to August but might also include April and September. One well-described nest was a dome made of spikerush (''

Eleocharis ''Eleocharis'' is a virtually cosmopolitan genus of 250 or more species of flowering plants in the sedge family, Cyperaceae. The name is derived from the Greek words ἕλειος (''heleios''), meaning "marsh dweller," and χάρις (''charis'' ...

'') within a stand of spikerush. The clutch size was five eggs.

Vocalization

The Aztec rail's courtship calls are a "loud, harsh series of 'kik' or 'kuk'" notes. Both sexes make "a series of 'chac' notes" as an "advertising call". The also give a "soft, rapid 'tuk'."

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 Aztec rail as Near Threatened. It has a moderate size range that might be expanding. However, its estimated population of 15,000 mature individuals is believed to be decreasing. Its freshwater marsh habitat is "under threat from increasing agricultural, industrial and urban development".

References

{{Taxonbar, from=Q18355759 Endemic birds of Mexico Rallus Birds described in 1874 Taxa named by Robert Ridgway Birds of the Trans-Mexican Volcanic Belt