Sirystes are highly distinctive flycatchers of low-to-middle elevation humid forest, and as a group are distributed from Panama south to Argentina and southeastern Brazil. Previously all populations were included in a single species, but song, and, to a lesser extent, the plumage, varies across the Neotropics, and now four species of sirystes are recognized. All sirystes are above with a pale rump; a black crown, wings, and tail; and white edging to the wing coverts and secondaries. Sibilant Sirystes is the easternmost species, occurring in central and eastern South America, south to northeastern Argentina and southern Brazil. It is not yet clear whether or where the distributions of Sibilant and White-rumped (Sirystes albocinereus) sirystes meet, but fortunately the two are readily distinguished. Sibilant Sirystes has a chattering song, very different from the whistled song of White-rumped; and Sibilant has darker plumage, with a gray throat, breast, and rump. All sirystes have the slender bodied, slightly crested appearance of Myiarchus flycatchers, and also share with Myiarchus the habit of nesting in tree cavities.