The trilling tapaculo (''Scytalopus parvirostris'') 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 Rhinocryptidae. It is found in

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 ...

and

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 ...

Taxonomy and systematics

The trilling tapaculo was previously considered a subspecies of unicolored tapaculo (''Scytalopus unicolor'') but was elevated to species status based on differences in their vocalizations. Though it is

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

, there are song variations in different parts of its range that suggest that there might be undefined subspecies.Krabbe, N. and Schulenberg, T.S. (1997). Species limits and natural history of ''Scytalopus'' tapaculos (Rhinocryptidae), with descriptions of the Ecuadorian taxa, including three new species. Pp. 46–88 in: Remsen (1997)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 19 January 2021. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved January 19, 2021Krabbe, N. and T. S. Schulenberg (2020). Trilling Tapaculo (''Scytalopus parvirostris''), 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.tritap1.01 retrieved April 30, 2021

Description

The trilling tapaculo is long. Males weigh and females . Adult males are usually dark gray above and lighter gray below, though sometimes dark gray all over. The flanks and crissum (the area around the

cloaca In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, a ...

) are dark reddish brown with dusky bars. The female is similar to the male but paler with a dark brown wash. The juvenile is similar to the female with the addition of a scaly appearance due to yellowish edges to feathers.

Distribution and habitat

The trilling tapaculo is found on the east slope of the Andes from southern Amazonas, Peru, southeastward to western Santa Cruz in Bolivia. It inhabits the undergrowth of humid

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

between the elevations of in Peru. In Bolivia it is found from and locally to .

Behavior

Feeding

The trilling tapaculo forages in dense undergrowth alone or in pairs, on or near the ground. Its diet has not been studied.

Breeding

Until a 2014 publication nothing was known about the trilling tapaculo's breeding biology other than that a juvenile was collected in July. In 2009 researchers discovered a nest in Peru. It was a globe with an outer layer mostly of small rootlets lined mostly with fern scales. It was constructed in a cavity in a rotten tree and contained two eggs. The authors monitored incubation but did not specify whether one or both adults incubated. The eggs hatched seven days after discovery and the nestlings disappeared soon after; they were too young to have fledged so the authors concluded that the nest had been predated.

Vocalization

The trilling tapaculo's song gives it its name. The trill's pace varies geographically, at 21 notes per second in central Per

14 in southern Per

and 20 to 28 in Bolivi

Its scold is similar but shorte

and it also has a single-note cal

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 trilling tapaculo as being of Least Concern. It has a large range, and though its population has not been quantified it is believed to be fairly large and stable.

References

{{Taxonbar, from=Q1270661 trilling tapaculo Birds of the Peruvian Andes Birds of the Bolivian Andes trilling tapaculo trilling tapaculo Taxonomy articles created by Polbot