zimmer's antbird Sciaphylax castanea

Scarce antbird found in rainforest understory in lowland and foothills of eastern Ecuador, northeastern Peru, and southern Colombia. Male is brown with a gray head, black breast, whitish belly, chestnut tail, and buffy wingbars; white patch on the back is usually concealed. Female’s breast is chestnut instead of black. Very similar to Chestnut-tailed Antbird, but note range and voice. Song is an accelerating, rising series of whistles; it sometimes falls in pitch near the end.