Spot-backed Antshrike

The spot-backed antshrike is a large antbird, 20 to 21 cm (7.9 to 8.3 in) long. The species exhibits slight sexual dimorphism. Both sexes have a short, heavy, gray bill with a hook at the end like true shrikes. Adult males have a black crown, nape, and upperparts spotted with white and a brownish black tail with white bars. Their throat and breast are white and their sides pale gray. Their belly and crissum are nearly white in the northern part of their range and gradually darken to brownish yellow to the south. Voice: The spot-backed antshrike's song is a "very high, slow, at first rising then descending, shivering rattle" that lasts four or five seconds. Its calls include a "long, downward-inflected whistle", a "shorter, slightly descending churr", and an "abrupt 'chip' ".