Translocation management of Leiopelma archeyi (Amphibia, Anura: Leiopelmatidae) in the King country

Abstract

Although conservation translocations are often recommended, they are expensive, require a long-term commitment and half of them fail. Moreover, in New Zealand, translocations have an additional cultural impact due to the Māori kaitiakitanga (guardianship) role. Thus, the main objective of this thesis was to improve the outcomes of a New Zealand native frog conservation translocation, analysing the case study of Leiopelma archeyi translocated from Whareorino to Pukeokahu (Waikato Region) in 2006 (70 frogs) and 2016 (60 frogs). To start this analysis, all the information related to the procedures carried out in each of the release events of this translocation were summarised and discussed. The results showed that the procedures related to the transport and captivity of the frogs were carried out at an acceptable standard. The components of capture and release of the frogs were slightly improved from 2006 to 2016, however, the mechanism of incorporating research into the procedures should be further improved to increase our knowledge of how to conduct successful conservation translocations. The first aim addressed in this thesis was to determine if the frogs were established (or not) in Pukeokahu by analysing the capture-recapture monitoring database managed by the Department of Conservation since 2007. Multiple problems were encountered in the analysis of this database, which was further complicated by the change of the monitoring procedure (from 2010 to 2014 and particularly on 2013) in reaction to a low number of frogs recaptured. Specifically, for this problem, one solution would be to increase the number of ‘consecutive’ monitoring secondary sessions, but most importantly, any change in the monitoring procedure would affect the accuracy of the demographic estimates calculated from that data. For Pukeokahu, this analysis indicated that there was an initial loss of individuals, either through emigration or death, and the frogs that remained were able to survive and slowly reproduce. Nevertheless, monitoring data is required at least until c. 2024 to assess the establishment of the population, and it is recommended to collect this data using the 2017 monitoring protocol (for four consecutive nights, 4-6 people search for frogs in an area of 280 m2). The second main aim of this thesis was to study the habitat of L. archeyi, and this was addressed in two ways: a comparative study of the resources available in the donor and release sites, and a natural history study of oviposition sites inside ponga (dead hollow tree-fern trunks). The results of these studies suggest that there is habitat in Pukeokahu (i.e. resources available for this species to survive), but not in the same abundance and conditions as in Whareorino. The main differences relate to humidity levels; the relative humidity was lower in Pukeokahu (in both, air conditions and retreat conditions), plus an irregular coverage of bryophytes in the trunks (i.e. bryophytes sensu lato require high levels of humidity in the environment for development). Given that the survival of adult frogs and breeding activity has been recorded for Pukeokahu, the results of this study suggest that although Pukeokahu supports habitat for this species, there is a heterogeneous distribution of resources, thus management actions to improve habitat are recommended (e.g. [i] add ponga with small diameters at the opening to increase availability of oviposition sites, [ii] build boardwalks to reduce the risk of squashing a frog during monitoring as the herbaceous stratum of vegetation is rapidly recovering inside the fenced area). The third aim of this thesis was to develop management actions in concordance with the cultural relevance of frogs for tangata whenua (local people). To do this, a partnership was established with tangata whenua represented by Ngāti Peehi and Ngāti Te Kanawa for the frogs in Whareorino, and represented by Te Hau Kainga o Pureora for the frogs in Pukeokahu. An important outcome of this partnership was the clarification of what would be a good process of communication and collaboration between tangata whenua and researchers (including DOC). As a result, a frog-hui (work meeting) was carried out in Te Kuiti, which provided the opportunity to meet together both whānau (family group) to discuss the thesis results. A description of Māori perspectives on conservation and the cultural impact of translocations is presented in the thesis. In conclusion, the PhD research offered a novel framework to analyse translocations, where the management actions recommended incorporates not only the biological aspects related to the survival and establishment of frogs in a novel site but also incorporate the cultural significance of these actions on the local community, which is essential to implement conservation in the long term.