SummaryThe occurrence, chronology of breeding and wing‐moult, and feeding habits of seven commonly occurring species of filter‐feeding ducks on the Kafue Flats in Zambia are described, based on 20 aerial surveys over the central section of floodplain and intensive observations on the ground at Lochinvar National Park, between October 1970 and January 1974.At high flood levels ducks were almost restricted to areas heavily utilized by lechwe; this association persisted until the floodplain became dry, but during the dry season ducks were also found on vegetated lagoons. Five species—Dendrocygna bicolor, Dendrocygna viduata, Thalassornis leuconotus, Netta erythropthalmaandAnas erythrorhyncha—were most abundant between June and September; a sixth—Anas punctata—was most abundant between December and March, while the seventh—Anas undulata—was probably resident. At times the numbers ofD. bicolor, D. viduataandA. erythrorhynchaprobably exceeded 25 000; those ofN. erythropthalmareached 6500, but the numbers ofT. leuconotus, A. punctataandA. undulatawere much lower and at Lochinvar did not exceed 500.Small numbers ofD. bicolor, N. erythropthalma, A. punctataandA. undulatanested on the floodplain in the vicinity of Lochinvar between March and July. All seven species completed their wing‐moult between April and October in the area; large numbers, particularly ofA. erythrorhynchaandD. bicolor, were involved.At Lochinvar,A. punctatafed mainly on aquatic invertebrates; the remaining species fed largely on shed fruits and seeds. The most important food plants were a terrestrial herb,Ambrosia maritima(January–April), two aquatic herbs,Nymphaea capensisandNymphoides indica(May–August), and two aquatic grasses,Echinochloa stagninaandVossia cuspidata(September–December). The herbs grew where grassland had been suppressed by lechwe; fruits of the aquatic grasses were found where lechwe had removed the overlying mat of stems. Despite similarities in diet the ducks differed from each other in feeding behaviour and/or preferred habitat.Five other species of filter‐feeding ducks,Anas capensis, Anas smithii, Anas clypeata, Anas acutaandAnas querquedula, have been recorded from th