Establishment, persistence and the importance of longitudinal monitoring in multi-source reintroductions

Incorporating genetic data into conservation programmes improves management outcomes, but the impact of different sample grouping methods on genetic diversity analyses is poorly understood. To this end, the multi-source reintroduction of the eastern bettong Bettongia gaimardi was used as a long-term case study to investigate how sampling regimes may affect common genetic metrics and hence management decisions. The dataset comprised 5307 SNPs sequenced across 263 individuals. Samples included 45 founders from five genetically distinct Tasmanian source regions, and 218 of their descendants captured during annual monitoring at Mulligan’s Flat Woodland Sanctuary (121 samples across eight generations) and Tidbinbilla Nature Reserve (97 samples across nine generations). The most management-informative sampling regime was found to be generational cohorts, providing detailed long-term trends in genetic diversity. When these generation-specific trends were not investigated, recent changes in population genetics were masked, and it became apparent that management recommendations would be less appropriate. The results also illuminated the importance of considering establishment and persistence as separate phases of a multi-source reintroduction. The establishment phase (useful for informing early adaptive management) should consist of no less than two generations and continue until admixture is achieved (admixture defined here as >80% of individuals possessing >60% of source genotypes, with no one source composing >70% of >20% individuals’ genotype) is achieved. This ensures that the persistence phase analyses of population trends remain minimally biased. Based on this case study, we recommend that emphasis be given to the value of generationally specific analyses, and that conservation programmes collect DNA samples throughout the establishment and persistence phases and avoid collecting genetic samples only when the analysis is imminent. We also recommend that population genetic analyses for multi-source reintroductions consider whether admixture has been achieved when calculating descriptive genetic metrics

Trends in animal translocation research

Translocations are an important conservation tool that enable the restoration of species and their ecological functions. They are particularly important during the current environmental crisis. We used a combination of text-analysis tools to track the history and evolution of the peer-reviewed scientific literature on animal translocation science. We compared this corpus with research showcased in the IUCNs Global Conservation Translocation Perspectives, a curated collection of non-peer-reviewed reintroduction case studies. We show that the peer-reviewed literature, in its infancy, was dominated by charismatic species. It then grew in two classical threads: management of the species of concern and management of the environment of the species. The peer-reviewed literature exhibits a bias towards large charismatic mammals, and while these data are invaluable, expansion to under-represented groups such as insects and reptiles will be critical to combating biodiversity loss across taxonomic groups. These biases were similar in the Translocation Perspectives, but with some subtle differences. To ensure translocation science can address global issues, we need to overcome barriers that restrict this research to a limited number of countries