This tyrannulet has yellow-bellied and whitish-bellied forms. Both use scrub and open woodland, avoiding closed forest. It ranges from Bolivia south to Argentina.
The yellow-bellied form has a gray crown and nape, white eyebrow and broken eye-ring, gray-olive upperparts, white crest and throat, gray breast, and yellow belly. The white-bellied form has whitish underparts and a more visible crown stripe when agitated.
It uses scrubby grassland, open woodland, tree groves, and gardens, avoids closed forest, and feeds mainly on insects.
An extinction-risk assessment has not been added yet.