pest eradication

Management of invasive mammal pests plays an integral role in the conservation of New Zealand’s native flora and fauna. Models fitted to pest capture data can guide conservation managers by providing estimates of pest densities within a management area, or probabilities of absence for declaring local eradication. A key parameter of these models is the detectability, i.e. the probability of an animal being detected by a surveillance device for a given amount of survey effort.

Feral pigs (Sus scrofa) were introduced to Auckland Island in subantarctic New Zealand in 1807. They established and became invasive, subsequently causing substantial unwanted impacts on native biodiversity. Understanding pig movement behaviour and habitat selection can lead to focused, efficient, and effective management efforts, especially during initial knockdown of the population. Here we used location data from ARGOS telemetry collars deployed on 15 Auckland Island pigs from 2007 to 2008 to estimate seasonal homerange sizes and habitat selection.

Norway rats (Rattus norvegicus) were present on Whale Island (Moutohora), Bay of Plenty, New Zealand between about 1920 and 1987. During 1969-1971 they reduced by less than 10-35 % the breeding success of grey-faced petrels (Pterodroma macroptera gouldi), by eating unattended eggs and killing young or weak chicks. Rabbits (Oryctolagus cuniculus), introduced to Moutohora (240 ha surface area) in about 1968, multiplied rapidly to reach a density of up to 375 individuals/ha by early 1973.