Wintering diving duck (Aythya spp.) time-activity budgets have been developed for many species in different regions. As such, direct comparisons can be made among studies where substantial deviations in “normal” activity budgets can provide insight as to how location, food resources, habitat, weather and human disturbance may differentially influence behavior (s) during winter. To examine how diving ducks use large reservoirs in eastern Texas, 1,275 individual time-activity budgets were quantified for Canvasback (Aythya valisineria), Lesser Scaup (A. affinis) and Ring-necked Duck (A. collaris) wintering on B.A. Steinhagen, Sam Rayburn and Toledo Bend Reservoirs during winter 2003/2004 and 2004/2005. Behaviors varied among species (P< 0.001), where food acquisition, locomotion and resting-related behaviors dominated time-activity budgets. All three species spent similar time feeding compared to other studies in the southeastern United States, but spent substantially more time locomoting than previously reported. Human disturbances from boat traffic were associated with time spent locomoting, but no species dramatically increased time feeding to compensate for increased time locomoting. Wintering diving duck activity budgets on these large eastern Texas reservoirs were generally similar to previous studies in the southeast. However, the (in) direct impacts of boat disturbances warrants closer investigation, specifically related to wintering waterfowl responses and the potential utility or value of voluntary avoidance areas during winter.