Also known by the longer moniker, Southern Chestnut-tailed Antbird, this member of the Thamnophilidae is widespread over much of Amazonia south of the Amazon River, from eastern Brazil to eastern Peru and northeastern Bolivia. It primarily inhabits the understory of upland terra firme forest and tall second growth, below 1350 m, but it locally occurs in seasonally flooded areas, and even transitional forest. The Chestnut-tailed Antbird appears to temporarily join mixed-species foraging flocks that transit its territory, but generally the species feeds alone or in pairs that maintain close contact, and always remain close to the ground. It also sometimes attends army ant swarms, to snatch fleeing arthropods and spiders. In contrast to its sister-species, the Zimmer’s Antbird (Myrmeciza castanea) of westernmost Amazonia, the present species is generally common to fairly common throughout its substantial range, which has to date been relatively little impacted by commercial logging.