Ten wood ducks (Aix sponsa) were radio-tracked during the wintering period on Steel Creek, Savannah River Plant, South Carolina. Home range size, daily movement and habitat use were determined from 1,140 radio-locations. Data collected during approximately 21 to 28 days of intensive radio-tracking were sufficient for delineating individual wintering wood duck home range size.. Males had significantly larger home ranges than females (42 ha vs 12 ha) and exhibited greater diurnal movements. Females made 0.5 to 3-day excursions (N = 10) to locations outside their home ranges throughout the entire tracking period. Wood ducks generally preferred emergent wetland habitat over scrub-shrub, forested, and open-water habitats. Emergent wetland habitat exhibited a more open canopy and greater herbaceous understory development than did other types. Preferred nocturnal roosting sites were located adjacent to feeding and loafing areas and were characterized by dense overhead and lateral cover. Some ducks made short flights <150 m) to roosting sites, but others did not. No radioequipped birds used communal roosts located on the study area.