SUMMARYThomas, D. G., and A. J. Dartnall. 1971. Moult of the Curlew Sandpiper in relation to its annual cycle. Emu 71: 153–158.Calidris ferruginea, in common with other long-distance migrants, moults flight feathers while in winter quarters. It requires 125–130 days to renew the primaries. A schematic representation of the annual cycle has been constructed from the fragmentary data available in the literature. It is shown that the only period free from physiological strain is that spent on the wintering grounds. Thus, the demands on reserves of energy to grow new feathers do not coincide with other events of the annual cycle that also make demands on reserves of energy.