Breeds in moist undergrowth and dense second-growth habitats, especially in or near riparian thickets.
Olive-green back, wings and tail; yellow below; males have a black crown. Females have black, beady eye, and lack wing bars and tail spots (compare with Yellow Warbler).
May breed in loose colonies. Nests on the ground, where it builds a bulky, cup-shaped structure. Invertebrates and occasionally berries constitute its diet.