Medium-sized, slim woodcreeper with a longish tail and shortish bill. Note the whitish eyebrow. Has a streaked head and upper back. Breast streaks have a triangular shape and dark edges. Inhabits the interior of seasonally flooded forests and forests on river islands; forages at middle levels, often accompanying mixed-species flocks. Sings a fast trill: “tr’r’r’r’r’r’r’r’r’r’r.” The similar, commoner Straight-billed Woodcreeper has a straighter, paler, and thicker bill, shorter tail, and slower song.