Human activity causes wintering waterfowl to expend energy to avoid humans at a time in their annual cycle when energy conservation is important to survival, migration, and breeding reserves. Understanding the effects of recreational activities on waterfowl is important to managing natural resource areas where migratory birds depend on wetland habitat for resting and feeding. We investigated responses of 7 species of dabbling ducks to 5 different experimental human activities, (a pedestrian, a bicyclist, a truck traveling at 2 different speeds, and an electric passenger tram). Responses of ducks depended on type of disturbance, species, and distance from disturbances. Most birds responded to the treatments. People walking and biking disturbed ducks more than vehicles did. Northern pintail (Anas acuta) was the species least sensitive to disturbance, whereas American wigeon (A. americana), green-winged teal (A. crecca), and gadwall (A. strepera) were most sensitive. Ducks were more likely to fly when closer to sources of disturbance. These results will be helpful to managers making decisions about public use that strive to minimize disturbance of dabbling ducks.