The timberline wren (''Thryorchilus browni'') 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 family Troglodytidae. It is found in

Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in the Central American region of North America, bordered by Nicaragua to the north, the Caribbean Sea to the no ...

and western

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...

Taxonomy and systematics

The timberline wren is the only member of genus ''Thryorchilus'', but its taxonomy at the subspecies level is unsettled. 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 ...

(IOC) considers it to be

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

Cornell Lab of Ornithology The Cornell Lab of Ornithology is a member-supported unit of Cornell University in Ithaca, New York, which studies birds and other wildlife. It is housed in the Imogene Powers Johnson Center for Birds and Biodiversity in Sapsucker Woods Sanctuar ...

's ''Birds of the World'' lists three subspecies, but notes that this treatment is disputed and that timberline wren should be "perhaps better considered monotypic."Kroodsma, D. E. and D. Brewer (2020). Timberline Wren (''Thryorchilus browni''), 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.timwre1.01 retrieved July 16, 2021 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 the

Handbook of Birds of the World The ''Handbook of the Birds of the World'' (HBW) is a multi-volume series produced by the Spanish publishing house Lynx Edicions in partnership with BirdLife International. It is the first handbook to cover every known living species of bird. Th ...

list the same three subspecies without comment.Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2019. The eBird/Clements Checklist of Birds of the World: v2019. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ Retrieved August 15, 2019HBW and BirdLife International (2020) ''Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world'' Version 5. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v5_Dec20.zip xls zipped 1 MBretrieved May 27, 2021 The three disputed subspecies are the nominate ''Thryorchilus browni browni'', ''T. b. ridgwayi'', and ''T. b. basultoi''.

Description

The timberline wren is long and weighs . The adult of the nominate subspecies has rich chestnut brown crown and upperparts and a reddish brown tail with thin dark bars. It has a broad gray-white

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 ...

, a chocolate brown stripe behind the eye, and grayish cheeks with narrow black markings. Its throat and chest are grayish white, its upper belly a mottled grayish white, its lower belly brown, and its flanks and vent area reddish brown. The juvenile is grayer below with a scalloped appearance. ''T. b. ridgwayi'' is larger than the nominate and has deeper reddish brown upperparts. ''T. b. basultoi'' has a wider supercilium, whitish markings on the upperparts and the sides of its neck, and has whiter underparts.

Distribution and habitat

The timberline wren's range is disjunct, and spans from central Costa Rica south to northern Panama. ''T. b. ridgwayi'' is found on Volcán Turrialba,

Volcán Irazú Volcan or Volcán may refer to: Places *Volcán, Panama, town in Panama *Volcán (Jujuy), town in Argentina Other uses *Volcan (mining company), Peruvian mining company *Volcán River, Chile *Volcán Lake, Bolivia People with the surname *Erin V ...

, and adjacent areas in central Costa Rica. ''T. b. basultoi'' is found in the Cordillera de Dota of south central Costa Rica. The nominate ''T. b. browni'' is found on

Volcán Barú The Volcán Barú (also Volcán de Chiriquí) is an active stratovolcano and the tallest mountain in Panama, at high. It lies about off the border of Costa Rica. It is also the twelfth highest peak in Central America. Due to its height and the ...

Volcán de Chiriquí Volcan or Volcán may refer to: Places *Volcán, Panama, town in Panama *Volcán (Jujuy), town in Argentina Other uses *Volcan (mining company), Peruvian mining company *Volcán River, Chile *Volcán Lake, Bolivia People with the surname *Erin V ...

, and Cerro Copete in western Panama. The timberline wren inhabits ''

páramo Páramo () can refer to a variety of alpine tundra ecosystems located in the Andes Mountain Range, South America. Some ecologists describe the páramo broadly as "all high, tropical, montane vegetation above the continuous timberline". A narrower ...

'' and near-''páramo'' moorland at the upper edge of tree line, and is partial to bamboo thickets. In elevation it mostly ranges between but can be found as low as .

Behavior

Feeding

The timberline wren typically forages on or near the ground, sometimes fluttering to pick prey from leaves and creeping along mossy branches. Its diet includes small insects, caterpillars, and spiders.

Breeding

The timberline wren's breeding season in Costa Rica spans from April to June. Its nest is a hollow ball constructed of bamboo leaves lined with finer material. It has a side entrance and is placed up in bamboo or a shrub. The typical clutch size is two.

Vocalization

The timberline wren's song is quite different from that of any ''Troglodytes'' wren; it is a repeated "series of half a dozen scratchy, warbling notes, lasting 2–3 seconds". Its call is "a harsh scolding 'churr'".

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 timberline wren as being of Least Concern. Though it has a restricted range, it is considered common to abundant in its habitat. Much of its range is in national parks and receives little human pressure.

References

{{Taxonbar, from=Q2225464

timberline wren The timberline wren (''Thryorchilus browni'') is a species of bird in the family Troglodytidae. It is found in Costa Rica and western Panama. Taxonomy and systematics The timberline wren is the only member of genus ''Thryorchilus'', but its ...

Birds of the Talamancan montane forests

Taxonomy articles created by Polbot