It is somewhat solitary in areas of open understory in varzea and terra firme lowland humid forest, primarily in the Orinoco and Amazon drainages.

The genus Ramphotrigon used to be considered to be related to Tolmomyias and Rhynchocyclus, two other genera of small tyrant flycatchers with broad bills .

It is found that Ramphotrigon is basal to a clade that includes Myiarchus (as well as Tyrannus and related genera), Call or day song is a low-pitched whistle.

The sharply two-toned basic pattern of the rufous-tailed flatbill - an olive-green bird with a bright rufous tail and wings - is distinctive and easily identifiable.

Compare to dusky-tailed flatbill (Ramphotrigon fuscicauda), which has dusky rectrices and remiges and a more heavily streaked breast.