White-throated tyrannulet
The name of this species refers to its appearance and means long-tailed bird and white eyebrow. Mecocerculus derives from the Greek terms mekos = long and kerkos = tail and leucophrys also from the Greek leukophrus = white eyebrow.
Taken from: Wiki Aves de Colombia.
Other references: Wikipedia, OpEPA, Handbook of the Birds of the World.