Description wikipedia

The grey-flanked cinclodes (Cinclodes oustaleti), formerly known as Oustalet's cinclodes, is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Argentina and Chile. The grey-flanked cinclodes is 17 to 18 cm (6.7 to 7.1 in) long and weighs 22 to 31 g (0.78 to 1.1 oz). It is a small cinclodes with a medium-length slightly decurved bill. The sexes have the same plumage. Adults of the nominate subspecies have a buff supercilium with speckles at its front, blackish brown lores and ear coverts, and a whitish malar area with dark scallops. Their crown is dark grayish brown and their upperparts rich dark brown. Their wings are also rich dark brown, with a whitish bend, tawny-rufous and blackish brown primary coverts, and some rufous across the base of the flight feathers. Their tail is blackish brown with dull rufous tips on the outer feathers. Their throat is white with dark scallops at its base and their breast dull dark gray-brown with pale spots on its upper part that become streaks below. Their belly is paler and browner than the breast and has a white center, and their flanks and undertail coverts are rich dark brown with some whitish feather tips. Their iris is dark brown to black, their bill blackish or blackish horn, and their legs and feet blackish brown. Subspecies C. o. hornensis is less richly colored than the nominate, with darker gray upperparts and grayer (less brown) underparts. C. o. baeckstroemii is like the nominate with the addition of a rufous tinge on the sides, flanks, and undertail coverts.