Trends and patterns in the extinction risk of Australia's birds over three decades

Australia recently committed through the Kunming-Montreal Global Biodiversity Framework (GBF) to halt human-induced extinction of known threatened species and to reduce extinction risk of threatened species significantly by 2030. We review recent trends in extinction risk of Australian birds to provide context for current and future conservation efforts. We calculate the Red List Index (RLI) for all Australian birds as well as subsets based on geography, habitat and taxonomy. Over the period 2010 to 2020, the number of taxa reassigned to lower categories of extinction risk (n = 20; 1.5% of all taxa included) was greatly outweighed by the number moved to higher categories owing to deteriorating status (n = 93; 7%). This resulted in the steepest decadal decline in the RLI since data were first compiled in 1990. It was chiefly driven by rapid population declines in migratory shorebirds, loss of suitable habitat for species affected by wildfire in 2019-2020 and, to a lesser extent, declines in the abundance of upland rainforest birds. To a small extent, these losses were counterbalanced by improvements in status of some bird species resulting from local eradication of invasive mammals, primarily from Macquarie Island. For Australia to meet the commitments recently adopted through the GBF, conservation interventions (and hence funding) will need to be scaled up substantially. The RLI is well placed for monitoring progress towards the GBF targets and for communicating trends in the extinction risk to national avifaunas. Australia is committed to reducing extinction risk through its adoption of the Kunming-Montreal Global Biodiversity Framework.A Red List Index (RLI) for all Australian birds from 1990 to 2020 shows their extinction risk increased by 3.34%.More than 50% of the increase in extinction risk between 2010 and 2020 was caused by the 2019-2020 wildfires.The greatest increases in overall avian extinction risk were in Queensland, South Australia and New South Wales, where drought and wildfire effects were most pronounced.Red List Index trends can reflect the impact of individual threats or conservation interventions, and represent an important tool for monitoring national and global progress towards international agreements.