The Lesser Elaenia uses open scrub and forest edges. In Bolivia it occurs alone or in pairs and eats fruit and arthropods.
It has gray upperparts, a bushy crest with a partly hidden white crown patch, two pale wing bars and a pale eye ring. Its gray breast grades into yellowish underparts.
In Bolivia it occurs alone or in pairs and eats fruit and arthropods. Some birds leave south-eastern Santa Cruz in autumn, while populations farther north are resident.
At Águas Emendadas in central Brazil in 2002–2003, nests were shallow cups of plant fibres, supported from below by forks of two or three branches.
Eggs at the same site were whitish to pale pink, with rusty to dark brown spots concentrated at the broad end. Clutches contained one to three eggs, most often two.
At the same site, the interval from laying the second egg to hatching of the first averaged 13.4 days in 17 nests.
An extinction-risk assessment has not been added yet.