Monitoring threats to Australian threatened birds: climate change was the biggest threat in 2020 with minimal progress on its management

ABSTRACT: Most biodiversity monitoring globally tends to concentrate on trends in species’ populations and ranges rather than on threats and their management. Here we review the estimated impact of threats and the extent to which their management is understood and implemented for all threats to all Australian threatened bird taxa. The assessment reports the situation in 2020 and how this differs from 2010. The most marked finding was that the impact of climate change has increased greatly over the last decade, and now surpasses invasive species as the threat imposing the heaviest threat load. Climate change has driven recent massive population declines from increased temperatures in tropical montane rainforests and from fire. For both direct climate change impacts and fire management, progress in understanding how to relieve the threats has been slow and patchy. Consequently, little effective management has occurred. By comparison, our analysis showed that the single successful campaign to eradicate introduced mammals from Macquarie Island relieved the total threat load on Australian threatened birds by 5%, and more than halved the load on the birds from oceanic islands. Protection or rehabilitation of habitat, particularly on islands, has also delivered measurable benefit as have, in the longer term, controls on longline fishing. Our approach can be used with other taxonomic groups to understand progress in research and management and to allow quantification of potential benefits from proposed actions, such as the national threatened species plan.

POLICY IMPLICATIONS ●Climate change is now the biggest threat to Australian threatened birds, but almost no research or management to mitigate this threat has been undertaken.●Most successful threatened species management has been on small islands with invasive species eradication, habitat protection and restoration providing substantial benefits. ●The approach taken can be used to quantify the benefits of both past conservation interven-tions and potential interventions. ●Monitoring trends in threat load complements indices assessing trends in population size and extinction risk.