Time-activity budgets and site selection of White-headed Ducks Oxyura leucocephala at Burdur Lake, Turkey in late winter

Diurnal and nocturnal time-activity budgets were complied for White-headed Docks at their most important wintering area, Burdur Lake in Turkey, during February and March 1993. During the day, ducks spent 28% of the time feedi ng, 57% resting 11% in locomotion, 4% preening and 1% in alert behaviour.. No courtship behaviour tons observed. Resting peaked in the middle of the d ay. As wave-height increased, feeding and swimming increased and resting de creased, Ar night, 92% of time was spent feeding. Sites used by White-heade d Ducks held a higher biomass of food it ems (benthic chironomid larvae) th an other parts of the lake. Movement of individuals and marked differences in diurnal time budgets occurred between sites, as birds concentrated in fl ocks for resting and dispersed to feed. The proportion of birds resting inc reased with the number of birds present, both within and between sites. Fee ding tons concentrated at those sites supporting a higher biomass of chiron omids for a given depth.