Breeding movements of black-fronted ternstarapirohe (Chlidonias albostriatus) caught on the Waiau ToaClarence River during the 2021 breeding season
The scale at which protected area networks have been considered in Aotearoa New Zealand has evolved from focusing on relatively small, representative ecological areas to developing aspirational landscape-scale restoration over the last c.50 years. However, the design of landscape scale protection has yet to consider the specific requirements of mobile species. Mobile species are those that use the environment at regional and national landscape scales, moving on a seasonal basis to exploit discontinuous (i.e., patchy) foraging and breeding resources and moving across rohe, takiwā, or territorial authorities’ jurisdictions.
There is a significant gap in our understanding of the extent to which threatened species are mobile at landscape scales, the threats they face, which require mitigation or management, and the challenges of accounting for their requirements in New Zealand’s conservation network. Mobile species are not just vulnerable to threats on their breeding sites, but across the habitats they use throughout the year. Research is needed to describe the spatial and temporal scales and patterns at which mobile species use the landscape. This includes identifying significant flyways and important habitat networks that need to be managed over the entire lifespan of the species.
The need for Territorial Local Authorities to identify the requirements of mobile species is described in the National Policy Statement for Indigenous Biodiversity Exposure Draft (Ministry for the Environment & Department of Conservation 2022). The objective of the National Policy Statement is to protect, maintain, and restore indigenous biodiversity, which includes responsibilities pertaining to mobile species. Draft Policy 15 notes that areas outside of Significant Natural Areas (SNAs) that support specified highly mobile fauna need to be identified and managed to maintain their populations across their natural range, and that information and awareness of specified highly mobile fauna needs to be improved.
Braided river birds are particularly mobile, moving between South Island inland breeding areas and the coast and northern harbours in winter. They are also, unlikely to reside on single rivers.
This study focusses on tarapirohe/black-fronted tern ([Chlidonias albostriatus] Threat classification: Nationally Endangered), which is listed in the schedule of ‘specified highly mobile fauna’ of the draft National Policy Statement (Appendix 2). Black-fronted terns breed only in braided river systems of the South Island and likely number fewer than 5000 mature individuals (Robertson et al. 2021). Migration routes between their breeding colonies and coastal wintering sites are currently unknown, making it difficult to provide a complete protection network for the terns. A recent study trialled new-generation miniature GPS tags to track the movements of black-fronted terns from breeding colonies in the inland Mackenzie Basin (Gurney 2022). This study indicated that tags had potential to identify important flyways and significant foraging and roosting habitats of black-fronted terns. These terns were highly mobile, foraging extensively within 25 km of their breeding colonies.