[4] The brown nunlet is found from south-central Colombia through eastern Ecuador into northern Peru.

[4] One nest of the brown nunlet was a trench excavated in the ground and roofed with sticks and leaves.

[4] Its close relative the rusty-breasted nunlet also nests in a shallow scrape that it covers with twigs and leaves.

The brown nunlet's song is "a series of 20–25 'treeu' notes, repeated steadily, starting quietly, building up, and then fading again towards end.

"[4] The IUCN has assessed the brown nunlet as being of Least Concern, though its population is unknown and believed to be decreasing.