The wedge-billed woodcreeper (Glyphorynchus spirurus) is a sub-oscine passerine bird in subfamily Dendrocolaptinae of the ovenbird family Furnariidae. It is found in Mexico, Central America, Brazil, Bolivia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela.
Taxonomy and systematics
The wedge-billed woodcreeper is the only member of its genus. It has these 13 subspecies that are sorted into three groups and a species by the Clements taxonomy:
"pectoralis" group
G. s. pectoralis Sclater, PL & Salvin, 1860
G. s. subrufescens Todd, 1948
G. s. pallidulus Wetmore, 1970
G. s. integratus Zimmer, JT, 1946
"spirurus" group
G. s. rufigularis Zimmer, JT, 1934
G. s. amacurensis Phelps, WH & Phelps, WH Jr, 1952
G. s. spirurus (Vieillot, 1819) G. s. coronobscurus Phelps, WH & Phelps, WH Jr, 1955 G. s. castelnaudii des Murs, 1856 "'albigularis"G. s. albigularis Chapman, 1923 "cuneatus" groupG. s. inornatus Zimmer, JT, 1934G. s. paraensis Pinto, 1974G. s. cuneatus (Lichtenstein, MHC, 1820)
The groups differ vocally; that and plumage and genetic differences among the subspecies suggest that the wedge-billed woodcreeper is actually more than one species.Marantz, C. A., A. Aleixo, L. R. Bevier, M. A. Patten, and D. A. Christie (2020). Wedge-billed Woodcreeper (Glyphorynchus spirurus), 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.webwoo1.01 retrieved May 28, 2023
Description
The wedge-billed woodcreeper is the smallest woodcreeper, with a short, upturned, wedge-shaped bill resembling those of the three members of genus Xenops. It is long and weighs . The sexes are alike. The nominate subspecies G. s. spirurus has a grayish forehead, a rich brown to russet-brown crown and nape, light buff lores, a thin buff to buff-white supercilium, a buff eyering, sooty-brown auriculars, and a brown malar stripe. Its upper back and scapulars are rich brown to russet-brown, and its lower back, uppertail coverts, and tail are cinnamon-rufous to rufous-chestnut. Its wing coverts are russet, its inner secondaries rufous, and its other secondaries and its primaries dark brown with blackish tips. The underside of most wing feathers have a stripe of buff to buff-white that shows as a band in flight. The sides of its neck are brown with small buff spots and its throat is whitish buff to buff with some dusky spots. Its underparts are olive-brown to russet-brown, its undertail coverts have a rufous-chestnut wash, and its underwing coverts and axillaries are white. Its upper breast has large round fulvous spots and its lower breast has narrow streaks of the same color. Its iris is dark brown to amber, its bill black with a gray base to the mandible, and its legs and feet pinkish gray, dark gray, dark greenish, or brownish black.
The other subspecies of the wedge-billed woodcreeper differ from the nominate thus:G. s. pectoralis, darker and more olivaceous underparts, cinnamon-buff throat, triangle markings on breastG. s. subrufescens, intermediate between pectoralis and pallidulus with little streaking on breastG. s. pallidulus, like pectoralis but paler overallG. s. integratus, paler than subrufescens, pale buff throatG. s. rufigularis, deep rufous throat, darker ochraceous wing band, less olive underparts than castelnaudiiG. s. amacurensis, paler and yellowish throat, more olivaceous crown and underparts, browner backG. s. coronobscurus, like rufigularis but with darker dusky brown crown and more olivaceous underpartsG. s. castelnaudii, darker and more olivaceous underpartsG. s. albigularis, narrower whitish throat and breast spotsG. s. inornatus, paler and buffier throat, browner spotting on throat, browner and unmarked bellyG. s. paraensis, like cuneatus but more olive-brown, rufescent tinge to throat markingsG. s. cuneatus, browner upperparts, paler throat with heavy markings
Several of the subspecies intergrade in their contact zones, making assignment of some sub-populations to a subspecies difficult.