It was described by Carl Eduard Hellmayr as Sclateria schistacea humaythae, a subspecies of the slate-colored antbird (now M.

[4] Later authors placed it as a subspecies of the spot-winged antbird (now M. leucostigma), which was successively placed in genera Percnostola and Schistocichla.

[5] A 2007 study of the vocal characteristics of the then many subspecies of the spot-winged found significant differences between the taxa.

Based on this evidence the Humaita antbird was promoted to species status and given its English name.

The Humaita antbird's song is a long trill that rises in pitch from start to finish and whose pace increases at the beginning, is steady in the middle, and decreases towards the end.

[9] The species' calls apparently are the same as those of the spot-winged antbird, which include a "long, downslurred, typically frequency-modulated whistle", an "abrupt unclear note given singly or in series of 2–5", and a "short rattle".

It occurs in Brazil's Humaitá Reserve, and its range also includes "extensive areas of intact habitat which are not formally protected, but seem unlikely to be threatened by development in the near future".