Moult, Movements, Age and Sex Composition of Mountain Duck, Tadorna tadornoides, Banded at Lake George, N.S.W

Abstract

Two samples of mountain ducks totalling 1001 birds were trapped and banded at Lake George,N.S.W. A highly significant difference in age structure between the two samples, taken in January 1965 and in February 1970, may be related to major differences in rainfall for the year preceding each sample. The sex ratio was markedly biased in favour of females. Recoveries of birds were nearly all to the south and west and 300-700 km from the banding site. Fully 99 % of recoveries were in States other than New South Wales. Examination of one sample of 679 mountain ducks for moult of primary and secondary wing feathers showed that approximately one-third of the adults were moulting. It was concluded that the birds were possibly normal residents of the region in which most recoveries occurred, and that they make an annual moult migration to Lake George.