Home ranges and interactions of kiore (Rattus exulans) and Norway rats (R. norvegicus) on Kapiti Island, New Zealand

Two species of rat (kiore or Pacific rat Rattus exulans and Norway rat R. norvegicus) coexisted on Kapiti Island (1965 ha) until 1996, when they were simultaneously eradicated. I radio-tracked rats of both species from June 1996 to September 1996, when the first of two aerial poison drops occurred. The aim of the study was to describe the home-range parameters of both species of rat in an area of grassland where they coexisted. Radio-tagged kiore occupied overlapping home ranges that varied from 26 to 89 m in diameter.