A strict Brazilian endemic, the Dark-winged Trumpeter is found in southeast and south-central Amazonia, from the Rio Madeira east to around the mouth of the Amazon, and south almost to the Bolivian border. It requires mature lowland forest in areas far from human settlements, or at least free of hunting. It is arguably the least-studied of the genus, with very few available data concerning diet or breeding, although there is no reason to suppose that the species’ ecology differs substantially from its congenerics. Like other trumpeters, it is group-living, sometimes occurring in large bands of up to 20 birds. Three races are recognized (and a fourth has been proposed), each of which is confined to a major interfluvial region south of the Amazon and which differ in the colour of the hindwing patch; recently, all three have been suggested to represent good phylogenetic species.