The Greater Wagtail-tyrant is a small, slender, long-tailed flycatcher of subtropical and tropical dry scrub in the chaco and adjacent areas of north-central Argentina, Bolivia, and Paraguay; with a small disjunct population in northeast Brazil. This species is fairly common in lowland scrub up to about 1000m, except in arid intermontane valleys in Bolivia, where it can reach up to 2700m, and can be quite easy to see as it moves actively through the undergrowth, often in pairs. The Greater Wagtail-tyrant is overall olive above and dull yellow below, with a lemon-yellow supercilium, and a black bill and a thin black mask. The distinctive long graduated tail often held slightly upward makes this species distinctive from most small flycatchers except for the Lesser Wagtail-tyrant (Stigmatura napensis) of the Amazon basin, with which it is almost entirely allopatric. This species can be heard giving a short, full, dry call in the underbrush, and the song is performed by both birds of a pair as a rambling, syncopated duet. Southern birds of central Argentina (flavocineria) are duller than northern birds, and lack the broad white band across the base of the underside of the tail which is present in northern birds. The nest is a small, simple cup of dried twigs about a meter from the ground, near the center of a thick, spiny shrub.