pukeko

Lethal control of wildlife is commonly used by conservation practitioners for population control. In some areas of New Zealand, changes in land-use and management have led to large increases in pukeko (Porphyrio melanotus melanotus) range and numbers. This native rail is sometimes considered a pest species, as they are known to uproot vegetation including tree seedlings, grass and crops. Here, we provide the first data on mortality during a lethal control operation that aimed to reduce pukeko population size at Tawharanui Regional Park in the North Island of New Zealand.

New Zealand's avifauna is characterised by a variety of endemic, often flightless, birds most of which are critically endangered. One of these, the takahe, is a large flightless rail which has been reduced to one population of 115 birds in its natural alpine habitat plus 52 others introduced on four small offshore islands. By contrast the takahe's closest extant relative, the pukeko, has been highly successful since its invasion of New Zealand within the past 800 years.

Numerical and spatial components of dispersion, and the activity of pukeko (Porphyrio p. melanotus) in swamp and pasture in coastal Manawatu, New Zealand, are described. Pukeko are concentrated in few locations during the autumn population peak, but are widely scattered in spring when the population size is minimum. Flocks are consistently larger in pasture than swamp; those of up to ten birds are more frequent in swamp. And those of 25 or more birds more frequent in pasture. In pasture, pukeko distribution and density declines outwards from the edge nearest to water.