Allison Binley , Lucas Haddaway, Rachel Buxton, Kristen Lalla, David Lesbarreres, Paul A Smith, Joseph R Bennett

Given widespread biodiversity declines, there is an urgent need to ensure that conservation interventions are working. Yet, evidence regarding the effectiveness of conservation actions is often lacking. Using a case study of 208 terrestrial species listed as Endangered in Canada, we conducted a literature review to collate the evidence base on conservation actions to: 1) explore the outcomes of actions documented for each species; and 2) identify knowledge gaps. Action-oriented research constituted only 2% of all literature across target species, and for 56% of species we found no literature investigating outcomes of conservation actions. Protected areas, habitat creation, artificial shelter, and alternative farming practices were broadly beneficial for most species for which these actions were assessed. Habitat restoration actions were most frequently studied, but almost 38% of these actions were harmful, ineffective, or demonstrated mixed results. The effectiveness of prescribed burns, alternative timber harvesting approaches and vegetation control was examined for the greatest number of species, yet 17-30% of these actions demonstrated negative effects. Our synthesis yielded a dataset of conservation evidence that can be implemented to aid in recovery planning for species at risk, and highlighted alarming gaps in the conservation literature that merit further investigation.