Курутія парагвайська Cranioleuca obsoleta

Restless long-tailed species with an olive-brown back, whitish chin, and buffy underparts. Note the whitish eyebrow, rusty wing patch, and rusty tail. Mostly found in the canopy of humid forests and second growth, including Araucaria forests, where it often accompany mixed-species flocks. The song is a repetitive and fast high-pitched series of “psee” notes, which gradually descends in a trill.