Predicting harvest impact and translocation success in endangered and highly mobile species: a case study of a critically endangered petrel

Abstract

**Abstract:** In endangered species, harvesting individuals for translocations can negatively impact source populations and thus, translocation cohorts should remain small, limiting potential establishment of recipient populations. This balancing act is further complicated through meta-population dynamics if the target species is highly mobile. The critically endangered Whenua Hou Diving Petrel (Kuaka; Pelecanoides whenuahouensis) is a highly mobile seabird that could benefit from translocations to mitigate current threats, but only one small population remains. We used a novel metapopulation approach to an integrated population model (IPM) to combine long-term data with meta-analyses and expert elicitations (using a Shiny app) to estimate vital rates, population size, population growth, and meta-population dynamics, predict harvest impact on the source, and project establishment of recipient populations under various translocation scenarios. Establishment of a recipient population without excessive impact on the source was dependent on meta-population dynamics. Accounting for juveniles returning to the source post-translocations mitigated impact on the source, but reduced establishment success of the recipient. Accounting for movements of adults and juveniles between source and recipient populations resulted in an equilibrium, negating effects of different harvests intensities. We illustrate that establishment of new populations of endangered, highly mobile seabirds can be feasible, even when metapopulation dynamics are present, yet our results also show considerable uncertainty. Therefore, we recommend that these challenging translocations are conducted within adaptive management frameworks, incorporating monitoring of source and recipient populations, to evaluate impact and establishment and adjust harvest intensities and timeframes when required. **Authors:** Johannes Fischer¹, Heiko Wittmer², Caio Kenup³, Kevin Parker⁴, Igor Debski¹, Graeme Taylor¹, John Ewen⁵, Doug Armstrong³ ¹New Zealand Department of Conservation, ²Victoria University of Wellington, ³Massey University, ⁴Parker Conservation, ⁵Zoological Society of London