The adult plumage of White-browed Antpitta is characterized by white lores and eyering, a buffy white postocular streak, and pale grayish olive auriculars. The crown is gray, the nape olive gray, and the rest of upperparts olive brown or olive grayish. In some adults, buffy wing-covert tips form two indistinct, rows of spots, visible to varying degrees. The wings are similar in coloration to the back, with a white edge, and side-by-side, roughly square, patches of black and ochraceous at the base of the primaries. The throat is white bordered by a dusky lateral throat stripe, and the upper breast is white, with prominent black streaking and spotting. The sides and flanks are buffy ochraceous.
The upright antpitta-posture, bold black markings on a white breast, and bright buffy lower parts make White-browed Antpitta nearly unmistakable within its range. The somewhat similar, and formerly conspecific, Speckle-breasted Antpitta (Hylopezus nattereri), lacks the postocular stripe and has a distinctly more speckled breast. The range of White-browed Antpitta, however, does not overlap with that of Speckle-breasted, or with any other Hylopezus antpittas.
Adult: The adult plumage of White-browed Antpitta is similar in both sexes and characterized by white or buffy white lores and eyering, and a narrow white or buffy white postocular streak. The postocular is thinly bordered with black, and the lores often include some black feathering. The auriculars are buffy olive or grayish olive with indistinct white shaft streaks. Above the plumage is mostly olive gray, more gray than olive on the crown. The wing coverts have light buff tips that sometimes are visible as two indistinct, rows of spots or broken wing-bars, but may not always be prominent. The primary wingcoverts are dark, contrasting with the ochraceous bases of the primaries, forming a distinct black-beside-ochraceous patch on the wing. The aula is bright white. The primaries and secondaries are similar in color to the lower back, somewhat more brownish, and the primaries have distinct ochraceous edging along the front margin. The throat and most of the breast are white except for a dusky lateral throat stripe and prominent streaks and spots across the breast. From the lower breast down, including the sides and flanks, the underparts are buffy ochraceous, with some of the breast streaking sometimes extending down into the buffy area, especially centrally. Central belly, undertail coverts, and thighs paler buff or whitish.
No specific information.
Iris: dark brown
Bill: black, with the basal half of the mandible paler
Tarsi and toes: pink to grayish pink
Total length: 12 cm (Narosky and Yzurieta 1989), 12.5 cm (Sick 1993), 13.5 cm (Ridgely and Tudor 2009), 14 cm (Sclater 1858, Meyer de Schauensee 1970, van Perlo 2009)
Sex unspecified –
wing length 76.2 mm; tail tail 38.1 mm; tarsus length 35.6 (n = 1, Sclater 1858)
Sex unspecified – 28 g (n = ?, Sick 1993)