The black-capped donacobius is the only member of the genus Donacobius and the family Donacobiidae. Its familial placement is not established, and ornithologists disagree as to its closest relations. A current proposal to the SACC would create a monotypic family, Donacobiidae, for this species, but this is not universally accepted as some authorities insist it may prove to be a member of an existing Old World family,
presumably the Locustellidae, which seem to be its closest living relatives. Black-capped donacobiuses are common in a wide range of Amazonian wetlands, including oxbow lakes, riparian zones, and other areas with tall dense aquatic or semi-aquatic vegetation. They often will engage in antiphonic dueting. Adult offspring will remain with their parents and help raise siblings from subsequent nesting periods in a system of cooperative breeding. Photo: Black-capped Donacobius.