World Bird List

Species factsheet
Chestnut-backed Antbird (Poliocrania exsul)

Order: Poliocrania exsul
Family: Antbirds (Thamnophilidae)

Voices can be found here (external link)
Subspecies and Distribution
Subspecie Distribution
exsul e Nicaragua to w Panama
occidentalis w Costa Rica and s Panama
cassini se Panama and n Colombia
niglarus e Panama and nw Colombia
maculifer w Colombia and w Ecuador