LAUSR

Monitoring threatened species is vital for effective conservation, and citizen science can fill information gaps where professionally derived monitoring data are unavailable or guide where further survey efforts may be warranted. Yet the geographic and taxonomic coverage of citizen science projects is poorly understood. Using a snapshot in time approach, we reviewed citizen science monitoring and survey projects in Australia in 2017 and identified 133 projects contributing to threatened species monitoring or conservation action in both terrestrial and marine environments. Most projects (61%) are relevant for 10 or fewer threatened species. Relevant citizen science projects tend to be concentrated along the more densely populated eastern and south-western coasts, while relatively few projects occur in northern regions of Australia. Our findings show a high convergence between citizen science project densities and threatened species richness in many terrestrial areas, although they also highlight areas with potential to expand citizen science, and indicate areas where professional monitoring is unlikely to be augmented by citizen science.