The yellow tyrannulet is a small passerine bird in subfamily Elaeniinae of family Tyrannidae, the tyrant flycatchers. It is found in Costa Rica, Nicaragua, Panama, and in every mainland South American country except Chile and Uruguay.
Region
Central and South America
Typical Environment
Occurs from southern Central America (Costa Rica, Nicaragua, Panama) through much of mainland South America, absent only from Chile and Uruguay. It uses lowland and foothill habitats including forest edges, second growth, thickets, and semi-open woodland. Frequently found along rivers, in gallery forests, and at the margins of wetlands and mangroves. It adapts well to lightly disturbed habitats, including hedgerows and shaded agricultural areas.
Altitude Range
Sea level to 1500 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 1/5
The yellow tyrannulet is a tiny tyrant flycatcher and the sole member of the genus Capsiempis. It favors edges and semi-open habitats where it actively gleans insects from foliage and makes short sallies. Its subtle olive-and-yellow plumage can make it easy to overlook despite being widespread. Vocalizations are often the best clue to its presence, with high, thin, repeated notes.
Temperament
active and somewhat skulking
Flight Pattern
short rapid wingbeats with brief sallies from low to mid-level perches
Social Behavior
Often seen in pairs or small family groups, and regularly joins mixed-species flocks in edge habitats. Maintains small territories during the breeding season. The nest is a small cup hidden in low shrubs or grasses, with both parents attending to the young.
Migratory Pattern
Resident
Song Description
Delivers high, thin, sibilant notes and short trills, often in rapid series. Calls include sharp tseep and tsee-tsee phrases that carry through edge habitats but can be easily overlooked among insect noise.
Plumage
Upperparts olive to olive-green with slightly duskier wings and two pale wing bars; underparts bright yellow from throat to belly. The face shows a faint pale supercilium and dusky lores, with a small, broad-based flycatcher bill. Tail is relatively short and often flicked.
Diet
Primarily feeds on small insects such as flies, beetles, and caterpillars, as well as spiders. Forages by gleaning prey from leaves and twigs and making short aerial sallies to snatch flying insects. Occasionally takes tiny berries when insect prey is scarce.
Preferred Environment
Most often forages in low to mid-level vegetation along forest edges, second growth, thickets, and riparian corridors. Also uses mangrove margins and semi-open agricultural landscapes with scattered shrubs and trees.
