A rarely encountered, mostly gray gnatcatcher of the canopy. Has slate gray upperparts and breast with a contrasting white belly, and a white eyering. Tail is long and slender with white outer feathers. Sexes similar. Restricted to white sand forests in lowlands Amazonia of Brazil, Colombia, and Venezuela. Actively moves through the canopy, often joining mixed species feeding flocks. Voice is a fast “fui fui fui fui.” Very similar to Guianan Gnatcatcher, but note differences in voice and range.