Population viability analysis informs Western Grasswren translocation: Multi-population sourcing of 112 founder individuals needed to meet success criteria

Conservation translocations have become an increasingly popular method to restore or secure vulnerable populations. However, translocations greatly vary in success. The use of population viability analysis (PVA) may increase the likelihood of meeting translocation goals. However, the quality of PVAs to inform translocations is dependent on the availability of ecological data and clear translocation objectives to guide them. Here, we used PVAs to inform the planned conservation translocation of the Western Grasswren (Amytornis textilis textilis) from mainland Shark Bay onto Dirk Hartog Island, Western Australia. A range of translocation scenarios were modelled and scored against success criteria as determined by translocation objectives. Simulations of 20-yr outcomes found that a minimum founder population of 112 individuals meet all success criteria. PVA supported sourcing individuals from 2 subpopulations to maximize genetic diversity. No impact to source populations was detected for the proposed harvest quantities despite conservative estimates of initial source population sizes. Here we demonstrate that creating clear, measurable objectives alongside a PVA lessens ambiguity about which translocation scenarios could be viable. In doing so, we have identified the minimum translocation sizes needed to maintain genetic diversity and population growth, thus increasing the likelihood of translocation success without impacting the source population. center dot Translocations, while increasingly popular as a conservation tool, are often prone to failure.center dot Population viability analysis (PVA) can inform the translocation planning.center dot We created various translocation scenarios through PVA analysis to inform how Western Grasswrens could be translocated onto Dirk Hartog Island, Western Australia.center dot Sourcing individuals from 2 populations yielded the best outcome for both source and founder populations.center dot We demonstrate that clear, measurable objectives alongside population viability analysis can help to identify which translocation scenario is most suitable for the target species. Las translocaciones de conservacion se han convertido en un metodo cada vez mas popular para restaurar o asegurar poblaciones vulnerables. Sin embargo, las translocaciones varian considerablemente en cuanto a su exito. El uso del analisis de viabilidad poblacional (AVP) puede aumentar la probabilidad de alcanzar los objetivos de la translocacion. Sin embargo, la calidad de los AVP para informar sobre las translocaciones depende de la disponibilidad de datos ecologicos y de objetivos claros de translocacion. Aqui utilizamos AVP para informar sobre la translocacion de conservacion de Amytornis textilis textilis desde la parte continental de Bahia Shark a la Isla Dirk Hartog, en Australia occidental. Se modelaron una serie de escenarios de translocacion y se evaluaron segun los criterios de exito determinados por los objetivos de la translocacion. Las simulaciones de resultados a 20 anos encontraron que una poblacion fundadora minima de 112 individuos cumple con todos los criterios de exito. El AVP respaldo la obtencion de individuos de dos subpoblaciones para maximizar la diversidad genetica. No se detecto impacto en las poblaciones fuente para las cantidades de cosecha propuestas, a pesar de las estimaciones conservadoras de los tamanos iniciales de las poblaciones fuente. Aqui demostramos que crear objetivos claros y medibles junto con un AVP reduce la ambiguedad sobre que escenarios de translocacion podrian ser viables. Al hacerlo, hemos identificado los tamanos minimos de translocacion necesarios para mantener la diversidad genetica y el crecimiento de la poblacion, aumentando asi la probabilidad de exito de la translocacion sin afectar a la poblacion fuente.