Eradication of Norway Rats (rattus Norvegicus) from Hawea Island, Fiordland, Using Brodifacoum

Norway rats were eradicated on bush-covered Hawea Island (9 ha) in Breaksea Sound, using the anticoagulant rodenticide "Talon 50 WB" (brodifacoum). The work was done as a conservation measure and to evaluate the feasibility and costs of eradicating rodents quickly from islands. The 50-100 rats present were eradicated in about two weeks by applying a simple strategy that took full account of the characteristics of the poison, the environment, and the behaviour of the target species. The technique used was designed to monitor its own progress, kill every rat as quickly as possible, continually detect the presence of surviving rats, limit the risk to non-target species, and overcome the many problems often associated with "getting the last rat".