Abstract: Recent estimates indicate that populations of Cerulean Warblers have declined precipitously over recent decades, and an estimated 70% of their global population is estimated to have been lost since 1966. Current conservation efforts are limited by our poor understanding of the ecology of Cerulean Warblers, especially on their wintering grounds. Cerulean Warblers overwinter in a narrow forest band in the Andes and are especially common in shade-coffee plantations, which are being rapidly converted to sun-coffee or pasture. This project will continue the most comprehensive study to-date of Cerulean Warblers on their wintering grounds. The primary goals are to (1) estimate within-season and annual survival rates of Cerulean Warblers and (2) identify key structural and floristic characteristics of foraging microhabitats of Cerulean Warblers in wintering habitats.