The Dull-mantled Antbird, a member of the Thamnophilidae family, is a modestly adorned species with a predominantly blackish-grey and reddish-brown plumage. Males and females are similar in appearance, though the female is slightly lighter and has a speckled throat. This bird measures approximately 13–14 cm in length and weighs around 24 grams.
In the dim light of its forest habitat, the Dull-mantled Antbird may seem uniformly black, save for distinctive white spotting at the wing-patch. Males have a blackish-grey head, neck, and upper mantle, with a black throat that features irregular spotting extending onto the breast. The female's throat is spotted with white and does not extend as far. Both sexes have a white patch between the shoulders with black specks.
The Dull-mantled Antbird is typically found in the understory and forest floor of tropical moist lowland forests. It prefers deep, damp ravines, slopes adjacent to streams, and areas with a densely vegetated herbaceous understory.
This species is found at elevations ranging from near sea level up to 1,500 meters above sea level, but most commonly between 300–750 meters.
The Dull-mantled Antbird forages close to the ground, often in pairs or small family groups. It feeds by gleaning insects from the leaf litter or vegetation, and occasionally follows army ants, though it is not an obligate ant-follower. It is known for its tail-beating behavior while foraging.
The male's loudsong is a rapid series of short notes, with the first few being upslurred or flat and the latter downslurred. The female's loudsong starts similarly but ends with deeper, muted notes. The species also emits short downslurred burrs and abrupt chip calls.
Breeding behavior is not well-documented, but the species is believed to have a prolonged breeding season. A nest described in Colombia was a simple cup placed low in a plant, containing two white eggs with cinnamon spots.
The Dull-mantled Antbird is closely related to the Esmeraldas Antbird and the Stubby-tailed Antbird, with which it shares several morphological traits.
Its diet consists of insects and other arthropods, including spiders, cockroaches, beetles, crickets, woodlice, and insect larvae. The bird employs a strategy of intense observation followed by direct strikes to capture its prey.
The Dull-mantled Antbird is currently listed as Least Concern on the IUCN Red List, indicating that it is not at immediate risk of widespread decline.