The Orinoco softtail (''Thripophaga cherriei'') is a

Vulnerable species A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, ...

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 Furnariinae subfamily of the ovenbird

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Furnariidae. It is found in

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 ...

and

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 ...

.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, G. Del-Rio, A. Jaramillo, D. F. Lane, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 28 September 2023. Species Lists of Birds for South American Countries and Territories. https://www.museum.lsu.edu/~Remsen/SACCCountryLists.htm retrieved October 20, 2023

Taxonomy and systematics

The Orinoco softtail 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 ...

. The Orinoco softtail's

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

honors

George Kruck Cherrie George Kruck Cherrie (August 22, 1865 – January 20, 1948) was an American natural history, naturalist and explorer. He collected numerous specimens on nearly forty expeditions that he joined for museums and several species have been named after ...

, who collected the first two specimens in 1899 on the

Orinoco River The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the wor ...

in Venezuela.Sharpe, C. J., J. V. Remsen, Jr., and P. F. D. Boesman (2022). Orinoco Softtail (''Thripophaga cherriei''), version 2.0. In Birds of the World (B. K. Keeney, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.orisof1.02 retrieved November 11, 2023

Description

The Orinoco softtail is long. The sexes have the same plumage. Adults have a faint buff or whitish

supercilium The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head.Dunn and Alderfer (2006), p. 10 Also ...

on a otherwise buff-streaked brownish face. Their forehead is brown with buff streaks and their crown medium brown with some faint yellowish spots. Their back is rufescent brown with a faint olive cast, their rump rufescent, and their uppertail

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 ...

reddish chestnut. Their tail is dark rufous to reddish chestnut. Their wings are mostly dark rufous chestnut with rufous-cinnamon at the base of the flight feathers. Their chin is a conspicuous tawny orange and their upper throat chestnut rufous. Their lower throat, neck, and breast are raw umber brown or olive brown with sharp buff streaks. Their belly is paler brown and their undertail coverts reddish rufous or ferruginous. Their iris is dark red, their bill gray to blackish, and their legs and feet dull pinkish olive.

Distribution and habitat

The Orinoco softtail was long thought to be

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 ...

to the area in south-central Venezuela where it was first collected. As of mid-2023, the

International Ornithological Committee The International Ornithologists' Union, formerly known as the International Ornithological Committee, is a group of about 200 international ornithologists, and is responsible for the International Ornithological Congress and other international ...

still lists it that way. However, in 2012 it was confirmed to be present in Colombia, in the departments of Guainía and Vichada adjacent to Venezuela. 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 ...

, the

Clements taxonomy ''The Clements Checklist of Birds of the World'' is a book by Jim Clements which presents a list of the bird species of the world. The most recent printed version is the sixth edition (2007), but has been updated yearly, the last version in 2022 ...

, and

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

list it as present in both countries. The full extent of its range has not been determined.Clements, J. F., P.C. Rasmussen, T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, A. Spencer, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2023. The eBird/Clements checklist of birds of the world: v2023. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved October 28, 2023 The Orinoco softtail inhabits the dense understory along watercourses in '' várzea'' forest. Vines and bamboo are important components of its habitat. It has a very small elevational range of between about above sea level.

Behavior

Movement

The Orinoco softtail is thought to be a year-round resident.

Feeding

The Orinoco softtail's diet has not been described. The one observation of a feeding bird described it foraging in dead leaves and on vines in the forest understory. It has been observed in

mixed-species foraging flock A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species that join each other and move together while foraging. These ar ...

s. Nothing else is known about its feeding behavior.

Breeding

The Orinoco softtail's breeding season had not been defined, but nest building has been documented in early March (early stages) and late November (near completion). The nests were bundles of sticks, rootlets, dead leaves, and other plant material suspended from a branch. Nothing else is known about the species' breeding biology.

Vocalization

The Orinoco sofftail's song "consists of 2‒4 nasal notes followed by a rattled series of short notes at a pace of about 15‒20 notes/second". It is typically sung in early morning and often in duet. The species' calls include a "strident grating scolding ''chrr''", a nasal "''chi-tew''", and "short ''chik'' and very faint ''chup'' notes".

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 ...

originally assessed the Orinoco softtail as Threatened but since 1994 has rated it as Vulnerable. It has a very small range, very specific habitat requirements, and an estimated population of 250 to 1000 mature individuals that is believed to be decreasing. "The principal threat appears to be loss of habitat through unsustainable, shifting cultivation practices." No part of its known range is protected.