About Synallaxis frontalis Pelzeln, 1859
The sooty-fronted spinetail (Synallaxis frontalis Pelzeln, 1859) measures 14 to 16 cm (5.5 to 6.3 in) long and weighs 11 to 17 g (0.39 to 0.60 oz). The sexes have identical plumage. On adult birds, the face is brownish gray except for a thin brownish line running through the eye. The forecrown, also called the front, is dark gray-brown; the hindcrown and nape are dark rufous; the back, rump, and uppertail coverts are brown with a rufescent tinge. Wing coverts are dark rufous, and flight feathers are tawny-rufous with dusky tips. The graduated tail is dark rufous, with darker inner webs on the innermost pair of feathers, and the individual tail feathers have slightly pointed tips. The chin is whitish, and the throat is grayer; lower throat feathers form a blackish crescent marked with pale speckles. The breast is grayish brown, the belly is paler than the breast, and the flanks and undertail coverts are browner than the breast and belly. Iris color is highly variable; the maxilla ranges from blackish to dark gray, the mandible ranges from gray to pale gray (sometimes with a blackish tip), and the legs and feet range from olive-gray to greenish gray. Juveniles have a brownish gray crown and an ochraecous wash on their underparts. Adults show clinal variation: plumage is brighter in the northeast of the species' range and becomes duller moving southwest. The sooty-fronted spinetail is distributed from northeastern Brazil (between Maranhão and Rio Grande do Norte) extending southwest in a wide swath through Brazil, eastern Bolivia, most of Paraguay, nearly all of Uruguay, and into Argentina as far as northern Buenos Aires Province. It lives in a variety of semi-open landscapes, including gallery forest, the edges of scrubby or deciduous forest, thorn-scrub, woodlands, and bushy savanna.
