The Narrow-billed Woodcreeper is a resident of deciduous forest and savanna from northeastern Brazil south to central Argentina. A medium sized woodcreeper with a slender decurved bill, the Narrow-billed Woodcreeper has a blackish-brown crown, a bold white supercilium, rufous-brown upperparts, and buffy white underparts with faint brown streaking. There are eight recognized subspecies, each of which varies slightly in the tone of color on the upper parts and the amount of streaking below. Narrow-billed Woodcreepers are most often encountered alone or in pairs, although these birds will at time join mixed species flocks. Like most woodcreepers, the Narrow-billed Woodcreeper forages by hitching up the trunks of trees gleaning insects and small vertebrates from the bark. Narrow-billed Woodcreepers can adapt to human altered environments, and have even been observed catching moths attracted to streetlights well before daybreak.