Schwartz's antthrush (''Chamaeza turdina''), also known as the scalloped antthrushHBW and BirdLife International (2024). Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 8.1. Available at: https://datazone.birdlife.org/species/taxonomy retrieved August 26, 2024, is a species of

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

in the family

Formicariidae Formicariidae is a family of smallish suboscine passerine birds of subtropical and tropical Central and South America known as antthrushes. They are between in length, and are most closely related to the ovenbirds in the family Furnariidae, an ...

. It is found in

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

and

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

Taxonomy and systematics

Schwartz's antthrush was long treated as a subspecies of the rufous-tailed antthrush (''C. ruficauda''). Their differences were not fully recognized until 1992 when their songs were analyzed in detail.Willis, E. O. (1992). ''Three Chamaeza Antthrushes in eastern Brazil (Formicariidae).'' Condor 94:110-116 Schwartz's antthrush 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 th ...

''C. t. turdina'' (

Cabanis Cabanis is a surname. Notable people with the surname include: * Bernard Cabanis (born 1950), French ice hockey player * George Cabanis (1815–1892), American politician * James Cabanis (1838–1920), American politician, son of George Cabanis *Jea ...

Heine Heine is both a surname and a given name of German origin. People with that name include: People with the surname * Albert Heine (1867–1949), German actor * Alice Heine (1858–1925), American-born princess of Monaco * Armand Heine (1818–1883) ...

, 1860) and ''C. t. chionogaster'' (

Hellmayr Carl Eduard Hellmayr (29 January 1878 – 24 February 1944) was an Austrian ornithologist. Biography Hellmayr was born in Vienna and studied at the University of Vienna, although he did not complete his degree. After his studies he worked in Vie ...

, 1906). The species' English name honors ornithologist Paul A. Schwartz, who was the first to realize how strikingly different its song sounds compared to that of the rufous-tailed antthrush.

Description

Schwartz's antthrush is long. The sexes are alike. Adults of the nominate subspecies have a slightly rufescent olive-brown crown. They have white lores, a short white streak through their eye, and a whitish streak on the side of their neck. Their upperparts and wings are mostly medium olive-brown with a slightly more rufescent rump. Their tail is dusky brown. Their throat is white with small blackish spots that look like a stripe. Their breast and belly are white with a heavy blackish scallop pattern. Their flanks have an olive-brown wash and their crissum has thin black bars. Their iris is reddish brown, their bill dusky with a reddish brown base to the

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

, and their legs and feet dusky brown. Subspecies ''C. t. chionogaster'' has paler underparts than the nominate with heavier scallops on their lower throat and breast; their tail feathers have thin pale buff tips.Krabbe, N. and T. S. Schulenberg (2020). Schwartz's Antthrush (''Chamaeza turdina''), 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.schant1.01 retrieved August 28, 2024

Distribution and habitat

Schwartz's antthrush has a highly

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 is found locally along all three of Colombia's Andean ranges, principally in the watersheds of the Cauca and Magdalena rivers. A separate population in the Serranía de los Yariguíes is thought to be this subspecies. ''C. t. chionogaster'' is found in northern Venezuela, in the Aroa Mountains and in the Coastal Range from

Carabobo Carabobo State (, ) is one of the 23 states of Venezuela, located in the north of the country, about two hours by car from Caracas. The state capital city is Valencia, which is also the country's main industrial center. The state's area is and ...

to northern Miranda. The species inhabits the interior and edges of humid to wet

montane forest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

. It favors areas with much moss and tangled understory vegetation. In Colombia it occurs between and in Venezuela between with a few sight records as low as .

Behavior

Movement

Schwartz's antthrush is believed to be a year-round resident throughout its range.

Feeding

The diet and foraging behavior of Schwartz's antthrush are not known in detail, though it probably feeds on insects and spiders. It is almost entirely terrestrial. It slowly walks and runs on the forest floor.

Breeding

The breeding season of Schwartz's antthrush varies geographically but is overall between May and August. Nothing else is known about the species' breeding biology.

Vocalization

In Venezuela, Schwartz's antthrush has two songs. One is "a remarkably long series of whistled ''cu'' notes...''without pause'', the series gaining slightly in volume, tempo, and pitch as it goes along". The other is "a loud abrupt and descending series of ''cuu'' or ''cuk'' notes that slow and wind down into a laughlike series of notes that stop abruptly or gradually merge into he other song. After either song it "sometimes gives a short series of chuckling notes at heend, e.g. ''cu-cu-cu, towak, wak, wak, wak''". It sings similar songs in Colombia. The species' calls include "a short 'quick' " and "a loud, abrupt ''ble'blink!''".

Status

The

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

has assessed Swartz's antthrush as being of Least Concern. It has a small range; its population size is not known and is believed to be stable. No immediate threats have been identified. It is considered fairly common in all parts of its range and occurs in several protected areas in both countries.

References

{{Taxonbar, from=Q859975 Chamaeza Birds of the Colombian Andes Birds of the Venezuelan Coastal Range Birds described in 1859 Taxonomy articles created by Polbot