The White-headed Marsh-Tyrant is a widespread species in tropical South America though absent from much of Amazonia. Sexually dimorphic, the male’s plumage consists of a stark white head and black body making it one of the most unique tyrant-flycatchers. The species has a strong ecological preference for slow moving or stagnant marshlands where it perches on reeds or small shrubs and sallies for flying insects. Its nest is a large, messy, globular construction of grass and feathers with a side entrance. Conspicuous and distinctive, the male White-headed Marsh-Tyrant is not likely to be missed or mis-identified in appropriate habitat, although the female should be compared with species of the genus Fluvicola.