Abstract:
Mammalian pest species pose a significant global threat to native fauna and flora, particularly to island ecosystems. The eradication of pest animals on offshore islands has been critical in protecting threatened species. Increasingly, pest eradication efforts have been steadily directed towards permanently inhabited islands. This situation presents added challenges of social complexity and divided land ownership to an inherently difficult management task. In 2019, the residential island of Kawau was selected by the regional government as a key candidate for multi-species pest eradication of rats, brushtail possums, stoats, and wallabies. This thesis investigated social and ecological aspects regarding pest management on inhabited islands. A questionnaire survey was conducted to assess residents’ (n = 43) and visitors’ (n = 84) perceptions of pests and pest management on Kawau Island. Nearly all pest animals were perceived to be highly damaging to native wildlife or native bush. However, wallabies were perceived to be the least favourable animal for control or eradication (Tukey HSD test; p < 0.001). While respondents were overall in favour of managing pests, this study identified that eradicating wallabies would likely be a source of social conflict. Using wildlife camera traps, I monitored the terrestrial animal community between two areas with opposite pest management regimes on Kawau Island. Furthermore, I investigated the population-level timing of activity for one pest genus: wallabies. I identified that in the area with selective wallaby control, there was over a 10 and 100-fold increase in possum and rat occurrences and a decrease in native bird occurrences. Observed diurnal activity within forests suggested habitat-dependent differences in the timing of wallaby activity. This thesis achieved its overarching aim in providing a scientific basis for future management actions and further research. Considering that the proposed pest eradication program on Kawau Island is still in its’ early stages, further public consultations, feasibility assessments, and monitoring studies were identified as important subsequent steps.
