It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela.

It was described and illustrated by the German ornithologist Jean Cabanis in 1847 and given the binomial name Hypocnemis poecilinotus.

Adult males of the nominate subspecies W. p. poecilinotus are mostly gray; their upperparts are darker than their underparts.

Their upperparts are mostly olive-brown with buff-edged brownish black patches on the lower back.

[11][12][13] Females of subspecies W. p. duidae have a black lower back and rump with wide white feather edges, a white-spotted black tail, reddish yellow-brown underparts with a cinnamon-rufous center to the belly, and olive-brown tinged flanks.

Females of W. p. lepidonota are similar to those of duidae but paler and with a browner crown and a light buff center to the belly.

[11] The common scale-backed antbird feeds mostly on a wide variety of arthropods; it has also been noted eating small lizards.

It captures prey mostly by short sallies from a perch to the ground but also to foliage, branches, and vines.

[11][13][14][15][16][17] The breeding season of the common scale-backed antbird varies greatly across its range, for instance spanning November to March in French Guiana and probably December to July in Ecuador.

It has been documented building several types of nests, including an open cup of dry leaves and other fibers in an understorey palm, a cavity lined with dead leaves, an unlined hollow at the top of a stump, and a cup of dried grass on the ground.

[16] Its calls include a "sharp 'psit'...a usually descending 'chirr', [a] more abrupt chitter, [a] short whistle quickly repeated 3–4 times, [and] also a longer whistle that falls and then rises in pitch, sounding like 'cherri' ".

[1] It is considered fairly common throughout its range, which includes many large protected areas.

"Regions occupied by this species also encompass extensive intact habitat which, although not formally protected, seems to be at little near-term risk.