Yungas Warbler

Male and female Yungas warblers have the same plumage. Adults of the nominate subspecies B. p. punctipectus have an olive-buff crown stripe that becomes buff gray on the nape, a long and wide black stripe below it, and a long white supercilium with a buff tinge below that. Their lores and ear coverts are black and they have a white crescent under the eye. Their cheeks are white and blend rearward to a small buffy spot behind the ear coverts. Their upperparts are olive gray. Their wings are dark brown with olive leading edges on the flight feathers and coverts. Their tail is dark brown with pale olive edges near the bases of the feathers. Their throat is whitish that becomes mostly yellow on the breast and belly. Their breast is mottled with olive gray. The sides of their breast and their flanks are pale olive gray and their undertail coverts yellowish gray. Subspecies B. p. inconspicuus has a slightly paler and whiter throat than the nominate with little or no mottling on the breast. B. p. canens has a whiter crown stripe, grayer upperparts, and whiter underparts than the nominate with less mottling on the breast. All subspecies have a dark iris, a horn-colored bill with a darker culmen, and pinkish to yellowish brown legs and feet.

Subspecies B. p. inconspicuus of the Yungas warbler is the most northerly of the three. It is found in the Andes from southeastern Peru's Department of Puno into northwestern Bolivia's La Paz Department. The nominate subspecies is found in central Bolivia's Cochabamba Department. Subspecies B. p. canens is found in eastern Bolivia's Santa Cruz Department. The species inhabits humid to wet primary and secondary forest from the foothills to cloudforest. It mostly ranges in elevation between 800 and 2,550 m (2,600 and 8,400 ft) but the nominate is thought to range up to 3,000 m (9,800 ft).

The Yungas warbler's diet has not been studied but is thought to be primarily invertebrates. Pairs or small family groups forage in the forest's understory, taking most food by gleaning from vegetation. It regularly joins mixed-species feeding flocks.