The Collared Gnatwren is a small forest bird with a long bill and a black breast band. It moves quickly through low growth in northern Amazonian forest while searching for insects and other arthropods.
The nominate subspecies has brown upperparts, a white eyebrow and cheeks, and black stripes through and below the eye. Its white underparts have a broad, crescent-shaped black breast band; the sexes are similar. Juveniles lack the band and bold facial markings.
It moves rapidly through humid lowland forest undergrowth, gleaning small arthropods from leaves and leaf litter. It sometimes joins mixed-species flocks and may follow army-ant swarms.
An extinction-risk assessment has not been added yet.