The fatty acid compositions of yolk lipids of eggs collected in the wild from five species of ducks (Anatidae) showing a range of dietary preferences, the king eider Somateria spectabilis, the lesser scaup Aythya affinis, the mallard Anas platyrhynchos, the green-winged teal Anas crecca and the gadwall Anas streperi, are reported. For all five species, the fatty acid profiles conformed to a similar pattern, characterized by relatively balanced proportions (w/w) of arachidonic (6.7–9.1%) and docosahexaenoic (5.9–7.0%) acids in yolk phospholipid. This contrasts markedly with the yolk phospholipid of current commercially-reared ducks where the proportion of arachidonic acid can be 10 times greater than that of docosahexaenoic acid. It was most notable that the similarities in yolk fatty acid profiles among the different species of wild ducks were achieved despite the considerable interspecies variation in dietary modes. It seems that, in this instance, genetic factors deriving from a common phylogeny may be more important than dietary differences in determining the fatty acid composition of yolk.