Swainson's Warblers (Limnothlypis swainsonii) have been described as terrestrial leaf litter foraging specialists, and are thought to vacate flooded areas entirely. We report Swainson's Warblers occupying a flooded area in Arkansas and foraging on unusual substrates. We observed Swainson's Warblers feeding in novel ways in the tree canopy and on floating debris. This is the first report of Swainson's Warblers occupying and foraging in flooded habitat, and suggests this species may have more short-term flexibility in foraging substrate than previously thought. Return rates to flooded territories were reduced compared to years without floods and several marked individuals switched to an unflooded area protected by man-made levees. The altered hydrology of rivers constrained by levees may reduce habitat quality for this species.