Rapid assessments accurately identify threatened Australian flora under IUCN Red List Criteria after megafires

The combined pressures of climate change and anthropogenic disturbance are increasingly pushing species toward extinction. However, many species remain unassessed for extinction risk, posing challenges to managers and decision makers when extreme events, such as megafires, impact large numbers of species. This has led to an increased need for rapid assessments, which can accelerate extinction risk assessments and help to ensure species receive timely conservation actions. In Australia, the 2019–2020 Black Summer fires had extensive impacts on native endemic flora, necessitating a prioritisation process to identify the species most in need of conservation interventions or extinction risk assessments. We used rapid assessments to identify priority species for full extinction risk assessments and compared how well the rapid assessments, with minimal information, predicted extinction risk in species that received a full assessment. Some 260 species received rapid assessments and 131 of these received full assessments. We found that 84 % of species identified as threatened by full assessments had been accurately identified as such during the rapid assessments. Rapid assessments also accurately predicted the specific threatened category in 53 % of cases compared to full assessments, however accuracy decreased with extinction risk (67 % for Critically Endangered, 54 % for Endangered, 11 % for Vulnerable). Our results show that rapid assessments can be a reliable and informative predictor of extinction risk and may be particularly useful in emergency circumstances. Recognising that effective conservation action relies on comprehensive and up-to-date threat listings, our results show the value of rapid assessments during biodiversity crises and highlight their utility to drive conservation actions.