This tyrant flycatcher has a bushy crest and yellowish lower belly. It catches insects by flying out from a perch and also eats fruit.
Adults have olive-brown upperparts and a white eye-ring. The bushy crest is prominent; the throat is pale, the breast greyish, and the lower belly pale yellow.
The study examined the subpagana subspecies. Researchers found three Yellow-bellied Elaenia nests near La Selva Biological Station in Costa Rica in March and April 2011. They followed one nest from egg laying until the single chick fledged, using a concealed camera to record about 21 hours of incubation and chick care.
Both parents fed the chick. On five occasions, a returning adult passed food to the parent sitting on the nest, which then gave it to the chick. Items brought to the nest included flies, beetles, stick insects, wasps, spiders, and berries. All three nests were shallow cups placed on branches 1.2–4.8 m above the ground and bound with spider silk. In the intensively observed nest, incubation lasted 15–16 days, and the chick fledged 14 days after hatching. The adult also ate the chick’s fecal sacs at the nest.
IUCN Red List · Least Concern (LC) · Global
The 2021.3 global IUCN Red List assessment classifies the Yellow-bellied Elaenia as Least Concern (LC). BirdLife’s Colombia country list also labels the species LC; that entry reflects the global category rather than a separate Colombian assessment.