Brightly-colored small leaf warbler with a strongly contrasting black-and-yellow head pattern. Bright yellow coloration all over the body distinguishes this species from most other leaf warblers. Very similar to Sulphur-breasted Warbler, but Yellow-vented has an off-white belly instead of a yellow one. Breeds in hill and montane broadleaf forests, often in wet areas with dense vegetation such as bamboo; descends into similar habitats in the foothills and lowlands in the winter. An active forager, often associating with mixed-species flocks during the non-breeding season. Often fans and jerks tail when calling. Song is mellow and pleasant: “wih-chew-chew-sip-sip-sip’pa’chew.” Calls include a soft “pitCHEW!”