Description wikipedia

The dark-bellied cinclodes (Cinclodes patagonicus) is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Argentina and Chile. The dark-bellied cinclodes is 18 to 20 cm (7.1 to 7.9 in) long and weighs about 36 to 50 g (1.3 to 1.8 oz). It is a largish cinclodes with a long decurved bill. The sexes have the same plumages, and the two subspecies differ very little. Adults of the nominate subspecies have a white supercilium that begins at the forehead, dark brown lores and ear coverts, and a white malar area with some faint darker flecks. Their crown and nape are dark brown and their upperparts a slightly lighter brown. Their wings are dark brown with blackish brown primary coverts. Their primary coverts and flight feathers each have a thin pale rufous-tinged white band. Their tail is dark brown; the outer three pairs of feathers have progressively more tawny-whitish on their tips. Their throat is whitish with faint darker specks and their underparts mostly dull dark brown. Their upper breast has pale spots that become streaks through the lower breast onto the upper belly. Their undertail coverts are dark brown with whitish tips. Their iris is dark brown, their bill brown to blackish, and their legs and feet brown to blackish. Juveniles are like adults with pale edges on the feathers of their back and less distinct breast markings. Subspecies C. p. chilensis is slightly smaller than the nominate, with buffier tips on the outer tail feathers and slightly browner underparts with less streaking on the belly.