Brown-billed Scythebill (Campylorhamphus pusillus) [XC572597]
by Iv\u00e1n Lau from El Copal Reserve, Costa Rica (song)
Brown-billed Scythebill (Campylorhamphus pusillus) [XC366808]
by Brendan Sloan from RNA Arrierito Antioque\u00f1o, Anor\u00ed, Antioquia, Colombia (song)
Subspecies
Central American subspecies considered by some authors to represent a separate species "Campylorhamphus borealis". Assessment of patterns of geographical variation complicated by individual variation in general coloration and in extent of streaking. Subspecies borealis and olivaceus poorly differentiated from one another. Variation upon which tachirensis and guapiensis based possibly individual rather than geographical.
The following 5 subspecies are recognised:
borealis Carriker, 1910 - Costa Rica (Caribbean slope, also in south-western on Pacific slope and adjacent lowlands) and western Panama (western Chiriquí, western Bocas del Toro).
olivaceus Griscom, 1927 - Central and eastern Panama (Veraguas east to eastern Darién).
tachirensis Phelps & Phelps Jr, 1956 - Perijá Mts and extreme eastern Andes in north-eastern Colombia and north-western Venezuela (western Zulia, south-western Táchira).
pusillus (Sclater, 1860) - Northern and central Andes on both slopes in Colombia (except extreme north-east) and Ecuador, and on eastern slope in northern Peru (south to Cajamarca and San Martín).
guapiensis Romero-Zambrano, 1980 - Coastal lowlands of south-western Colombia (Cauca).
BirdLife International Species Factsheet