Maximizing the effectiveness of qualitative systematic reviews: A case study on terrestrial arthropod conservation translocations

Systematic literature reviews are frequently used in biodiversity conservation to identify knowledge gaps and strategies for improvement. Despite their important role, systematic reviews are not standardized and often use different methods, standards for success, and data sources. We compared two systematic reviews on terrestrial arthropod conservation translocations, unknowingly conducted by two research groups at the same time. Both studies found geographic and taxonomic biases, with most projects focusing on certain countries (e.g., United States, United Kingdom) and taxa (e.g., butterflies, grasshoppers), and found similar success rates (range: 52–58%). However, the studies had different conclusions about which factors significantly influenced translocation success, driven by the data sources used (published literature vs. data from corresponding authors). Release numbers reported by corresponding authors were approximately double those in the published literature, causing the two studies' data sets to differ dramatically. The results show that improved communication among researchers and practitioners is needed to ensure access to current data and prevent duplication of efforts. We recommend that: i) planned, ongoing, and unpublished work be integrated as best possible in reviews; ii) expert perspectives be included alongside quantitative measures; iii) online tools be used more to promote communication; iv) an online catalogue of translocation projects be established to facilitate awareness and contact among researchers; and v) standardization of translocation reporting be increased. We provide practical pathways and actions to help achieve these recommendations. These improved review practices can benefit both systematic reviewers and conservation practitioners by increasing the quality and accuracy of systematic reviews.