A small, pale, and active tyrannulet with a small bill. No bright colors; look for bold white eyebrow, pale yellowish rump, and two off-white wingbars. Tends to perch horizontally, often with its tail cocked up slightly. Flits actively, usually in the canopy and often part of a mixed-species flock. Occurs in cloud forest and edges from Colombia to Peru, from around 1,500 to 2,500 m. Similar to White-banded Tyrannulet, but smaller and found at lower elevations; also note White-banded’s thicker white eyebrow, gleaming white wingbars, and generally more contrasting plumage than White-tailed. Often detected by series of three or four squeaky “psee” notes coming from a canopy flock.