Red-billed Scythebill (Campylorhamphus trochilirostris) [XC415196]
by Yair Guillermo Molina Mart\u00ednez. from Pilcomayo, Formosa, Argentina (song)
Red-billed Scythebill (Campylorhamphus trochilirostris) [XC722066]
by Jacob Wijpkema from Santa Rita do Novo Destino, Goi\u00e1s, Ch\u00e1cara Jayrson, Brazil (call)
Subspecies
Suggested as sister-species of Curve-billed Scythebill (Campylorhamphus procurvoides), with relationships among some taxa in group unclear. Specimens of Curve-billed Scythebill (Campylorhamphus procurvoides) south-eastern Amazonian subspecies multostriatus are intermediate between the two species, while its southern subspecies are vocally more similar to present species. Also close to Black-billed Scythebill (Campylorhamphus falcularius), and sometimes regarded as forming a superspecies with it or even as conspecific. Assessment of geographic variation and separation from Curve-billed Scythebill (Campylorhamphus procurvoides) both complicated by marked individual variation in general coloration and in extent and width of streaking above and below, but at least three geographically isolated groups evident: "venezuelensis group" (with brevipennis) in eastern Panama and northern South America, "thoracicus group" (with zarumillanus) along Pacific coast of South America, and "trochilirostris group" (including remaining races) from Amazonia, Atlantic forest and dry interior of South America. In last-mentioned group, affinities of Amazonian subspecies problematic; napensis morphologically closest to "thoracicus group" of Pacific coast, whereas notabilis, snethlageae and devius apparently closer to lafresnayanus of dry interior, which region also includes hellmayri and major; described subspecies omissus (eastern Brazil) and guttistriatus (southern Goiás, Brazil) both synonymized with major.
The following 12 subspecies are recognised:
brevipennis Griscom, 1932 - Central and eastern Panama (northern Coclé and eastern Panamá east to Darién) and north-western Colombia (Pacific coast south to northern Chocó).
venezuelensis (Chapman, 1889) - Locally in northern Colombia from Córdoba east to Magdalena Valley (south to northern Huila), Caribbean lowlands and east of eastern Andes (Norte de Santander south to western Meta), and northern and central Venezuela (east to Sucre, south to R Orinoco; locally in north-western and southern Bolívar); reports from French Guiana apparently refer instead to Curve-billed Scythebill (Campylorhamphus procurvoides).
thoracicus (Sclater, PL, 1860) - Coast of south-western Colombia (south-western Nariño) and western Ecuador.
zarumillanus Stolzmann, 1926 - Coast of extreme north-western Peru (Tumbes, Piura).
napensis Chapman, 1925 - Western Amazonia in eastern Ecuador and eastern Peru.
notabilis Zimmer, JT, 1934 - Western Amazonian Brazil south of Amazon, between lower R Purús and lower R Madeira.
snethlageae Zimmer, JT, 1934 - Central Amazonian Brazil, on both banks of Amazon from R Madeira east to R Tapajós, including islands in Amazon R.
devius Zimmer, JT, 1934 - South-western Amazonia in northern Bolivia; populations in adjacent south-eastern Peru and western Brazil (Acre, south-western Amazonas) may represent this subspecies.
lafresnayanus (d'Orbigny, 1846) - Central South America in eastern Bolivia (Santa Cruz), south-western Brazil (western Mato Grosso, western Mato Grosso do Sul, possibly farther east) and western Paraguay (south to R Pilcomayo).
hellmayri Laubmann, 1930 - South-western Paraguay (í‘eembucú) and northern Argentina (Salta, Formosa and western Corrientes, south to La Rioja, Santiago del Estero, northern Santa Fe and Entre Ríos).
major Ridgway, 1911 - Interior eastern and southern Brazil, from Piauí and Ceará south to Minas Gerais and extreme western Paraná.
trochilirostris (Lichtenstein, 1820) - Coastal eastern Brazil from Pernambuco south to south-eastern Bahia (Ilhéus).
BirdLife International Species Factsheet