A brown, tree-climbing bird with a strongly curved bill. Appears small-headed; plumage is mostly rufous-brown with heavy white streaking on head, neck, and back. Found in tall rainforest, where it is uncommon and locally distributed; often occurs in areas with extensive bamboo thickets. Generally shy and rather difficult to observe. Forages at middle and upper levels, using extraordinary bill to probe into deep bark crevices, bromeliads, and broken bamboo stems. Regularly follows mixed-species flocks. Song is regionally variable; in most of range it is a strident, rubbery trill, often preceded by one or two longer notes to form an accelerating series on one pitch. Curved bill should immediately distinguish this species from other woodcreepers in range. In western and central Amazonia, may overlap with Red-billed Scythebill, from which it may not be safely separable unless singing (song of Red-billed does not increase in pitch).