The kuaka Whenua Hou (Whenua Hou diving petrel; Pelecanoides whenuahouensis) is a critically endangered burrow-nesting petrel with a population of ~200, restricted to breeding in the foredunes of Whenua Hou (Codfish Island), in southern Aotearoa New Zealand. Population recovery continues to be inhibited by offshore threats, particularly vessel-based light pollution, and is likely to face additional pressure from the growing interest in offshore developments in southern Aotearoa. Understanding their at-sea distribution during the breeding period is especially important, as central-placed foraging constraints require adults to regularly return to the colony, making them particularly vulnerable to localised threats. To safeguard kuaka Whenua Hou it is crucial to ensure that current and future offshore threats are managed effectively. This thesis presents the first fine-scale GPS tracking study of kuaka Whenua Hou during the breeding period, conducted across two consecutive years (2023 and 2024), tracking ~20% of the global population. These data provide critical insights into their spatial ecology, habitat use, and overlap with current and potential future offshore threats. Tracking results revealed consistent space use within Te Ara a Kiwa (Foveaux Strait) and adjacent offshore regions, highlighting the ecological importance of this region for kuaka Whenua Hou. Core use areas were concentrated near the breeding colony and into Te Ara a Kiwa, and home ranges extended south of Rakiura (Stewart Island), towards Tini Heke (Snares Island) and the Snares Shelf, and westward towards the Puysegur Trench. Trip metrics varied by breeding stage, with shorter, daily commutes during pre-breeding and chick-rearing, and longer trips during incubation. No sex based differences were detected, reflecting the species’ monomorphic body size and presumed shared parental roles. Spatial overlap analyses identified areas of concern where kuaka Whenua Hou movements coincide with current and potential future offshore threats, including vessel-based light pollution, areas potentially suitable for offshore wind farms (OWFs), and potential future aquaculture installations. Vulnerability to artificial light at night (ALAN) was highlighted by overlap with nocturnal vessel activity, with areas of current potential risk identified around Whenua Hou, south-west of Rakiura, and a small cluster north-west of Hautere (Solander Island). Areas potentially suitable for OWF developments showed substantial overlap with core use areas, raising concerns about collision risk, displacement from important foraging habitats, and increased energetic costs. Overlap with potential future aquaculture installations was overall low but varied by site, with Rarotoka and Hananui sites showing higher interactions during chick-rearing. These findings emphasise the urgent need for precautionary, species-specific management to mitigate cumulative risks from multiple offshore pressures. Recommended mitigation includes ALAN reduction on vessels, strategic placement and operational restrictions of OWFs, and careful site selection and lighting designs for aquaculture. Future research should incorporate vertical movement data and expand spatial and temporal coverage to better understand foraging behaviour and threat exposure. Overall, this thesis provides an essential foundation for marine spatial planning and conservation policies aimed at safeguarding the long-term viability of kuaka Whenua Hou amidst increasing offshore development and environmental change.
Te Arawhetu Waipoua (Thu,) studied this question.