Use of Pukepuke lagoon by waterfowl.

This is a preliminary account of some basic waterfowl population studies being undertaken at Pukepuke Lagoon, the first such studies so far attempted in New Zealand. Attention has been focussed on the popular game species of duck; the introduced mallard (Anas platyrhynchos platyrhynchos), the native grey duck (Anas superciliosa superciliosa) and New Zealand shoveler (Anas rhynchotis variegata). Seasonal fluctuations in population density, sex-ratios, nesting season chronolgy and the influence of water levels on hatching success are discussed