South-eastern Colombia (Meta, Caquetá, Putumayo, southern Amazonas), eastern Ecuador, north-eastern and east-central Peru (Loreto, Amazonas, northern Ucayali) and western Amazonian Brazil (east to R Japurá and to both banks of R Juruá).
Population
Estimated population is unknown (2010).
White-shouldered Antbird (Akletos melanoceps) [XC435899]
by Jerome Fischer from Reserva Natural Palmar\u00ed, Rio Javar\u00ed, AM, Brazil (song)
White-shouldered Antbird (Akletos melanoceps) [XC742805]
by id from Sani Lodge, Sucumb\u00edos, Ecuador (song)
Subspecies
Genus appears not to represent a monophyletic grouping, but traditional arrangement maintained pending further phylogenetic study. Considered closely related to Goeldi's Antbird (Akletos goeldii), with similarities in morphology and voice, but differences in location of hidden white patches and possibly in nest architecture may indicate more distant relationship. The two appear to be sympatric in Brazil along upper R Juruá (Acre). Both species and Plumbeous Antbird (Myrmelastes hyperythrus), Sooty Antbird (Hafferia fortis) and Blue-lored Antbird (Hafferia immaculata) often thought to form a species group on basis of large size, but more work needed in order to confirm a close relationship among them.
BirdLife International Species Factsheet