We used time-activity budget techniques to measure foraging behavior of green-winged teal (Anas crecca carolinensis) and mallards (A. platyrhynchos). Observations were made on tidal mudflats in the Atchafalaya River Delta, Louisiana, USA, in the winter of 1994–1995. Green-winged teal spent more diurnal time than mallards foraging (68% vs. 35%). Time spent in different foraging postures also differed between species. Green-winged teal foraged by dabbling 70% of the time and by head-dipping only 28% of the time. Mallards foraged by dabbling 47% of the time and by head-dipping 47% of the time. Foraging by tipping-up was rare in both species. Mean water depths used by both species when foraging were <5 cm. Most foraging took place near the mud-water interface during ebb and flow tides.