It breeds in tropical South America from Colombia, Venezuela and Trinidad south to Bolivia, Argentina and Paraguay.
This species is found in marshy savannahs, reedbeds and the edges of mangrove swamps.
Breeding / Nesting
The nest is a feather-lined oval ball of grasses and other plant material, with a porched side entrance. It is placed at the end of a branch near or over water. Both sexes incubate the typical clutch of two or three creamy-white eggs, which are marked with a few brown spots. Cowbirds often parasitise the nest.
The adult White-headed Marsh Tyrant is 12.7 cm long and weighs 15 g. The male is entirely brown-black, apart from the relatively large white head and yellowish lower beak.
The female has brown upperparts and wings and a black tail. Her underparts, sides of the head and forecrown are dull white.
Calls / Vocalization
This is a quiet species, but the call is a sharp sedik.
Diet / Feeding
White-headed Marsh Tyrants wait on an exposed perch in marsh vegetation or a branch near water, occasionally sallying out to feed on insects, their staple diet, before returning to the perch.