Endemic to a small part of Amazonian Brazil, the Klages’s Antwren is found in the states of Amazonas, Pará, and Roraima, but is further confined to relatively small parts of four major rivers within this region, the Solimões (Amazon) where it reaches as far downstream as the mouth of the Rio Tapajós, the Madeira, the Negro, and the Branco, on which last-named river it was only relatively recently discovered. Fairly common or even common within this range, this antwren is confined to the canopy and subcanopy of lowland seasonally flooded forests, where it is easily attracted by playback. It is typically found in pairs or alone, but to date there is no evidence that the species joins mixed-species foraging flocks. The species is generally very similar in plumage to the Amazonian Streaked-Antwren (Myrmotherula multostriata) and the Cherrie’s Antwren (Myrmotherula cherriei), but it is apparently only partially sympatric with either. The species’ unusual vernacular and scientific names commemorate the feats of the professional American collector, Samuel Klages, who subsequently died in relative penury in the late 1950s, but whose live is also remembered in the scientific names of several insects. BirdLife International currently considers Klages’s Antwren as Near Threatened.