Abstract: Diurnal time-activity budgets of White-headed Ducks were investigated with respect to sex and temporal environmental variables to document behavioral responses to winter conditions and nutritional requirements at Burdur Lake where the largest winter concentrations occur. Behaviors of males and females were recorded separately in randomly selected focal flocks during 1140 sessions. For the entire population a large proportion of time was spent resting. During the day they spent 61% of time resting, 22% feeding, 12% comfort and 5% in locomotion. Resting peaked in the middle of day while feeding was observed frequently in evening and morning. Time use did not differ significantly between sexes. However, it was detected that more time was spent feeding during windy days as wave-height increased.