Fragmented evidence for the contribution of ex situ management to species conservation indicates the need for better reporting

Abstract

Abstract Conserving species and achieving the Convention on Biological Diversity's international conservation targets necessitates stopping extinctions, recovering depleted populations and maintaining viable populations. The contribution of ex situ management to species conservation has long been debated, and there is limited information on ex situ management activities available in a format that allows success to be assessed. We therefore gathered information from three sources to explore cases in which ex situ management was considered to have had a positive conservation impact for terrestrial vertebrate species. We (1) reviewed the published literature, (2) examined for which taxa ex situ management had contributed to the downlisting of species on the IUCN Red List and (3) surveyed a global network of ex situ management practitioners. We found that ex situ management has contributed to improvements in conservation status for a range of vertebrate species. Ex situ management was reported as contributing to the downlisting of 18 species on the IUCN Red List over a 10-year period. Across sources, the most common role of ex situ management was the provision of individuals to increase population numbers in situ. The strength of evidence for the impact of ex situ management varied within and among sources. Therefore, for the role of ex situ activities in conservation to be understood fully, and for such interventions to reach their potential, documentation of intended and actual benefits needs to be improved. Better reporting of ex situ activities would enable improved learning, facilitating better targeting of ex situ activities to global species conservation goals.