The conservation impacts of ecological disturbance: Time‐bound estimates of population loss and recovery for fauna affected by the 2019–2020 Australian megafires
Authors: Legge Sarah , Rumpff Libby , Woinarski John C. Z. , Whiterod Nick S. , Ward Michelle , Southwell Darren G. , Scheele Ben C. , Nimmo Dale G. , Lintermans Mark , Geyle Hayley M. , Garnett Stephen T. , Hayward‐Brown Brittany , Ensbey Miki , Ehmke Glenn , Ahyong Shane T. , Blackmore Caroline J. , Bower Deborah S. , Brizuela‐Torres Diego , Burbidge Allan H. , Burns Phoebe A. , Butler Gavin , Catullo Renee , Chapple David G. , Dickman Christopher R. , Doyle Katherine E. , Ferris Jason , Fisher Diana , Gallagher Rachael , Gillespie Graeme R. , Greenlees Matt J. , Hohnen Rosie , Hoskin Conrad J. , Hunter David , Jolly Chris , Kennard Mark , King Alison , Kuchinke Diana , Law Brad , Lawler Ivan , Lawler Susan , Loyn Richard , Lunney Daniel , Lyon Jarod , MacHunter Josephine , Mahony Michael , Mahony Stephen , McCormack Rob B. , Melville Jane , Menkhorst Peter , Michael Damian , Mitchell Nicola , Mulder Eri , Newell David , Pearce Luke , Raadik Tarmo A. , Rowley Jodi J. L. , Sitters Holly , Spencer Ricky , Valavi Roozbeh , West Matt , Wilkinson David P. , Zukowski Sylvia 
Published: March 2022

Aim

After environmental disasters, species with large population losses may need urgent protection to prevent extinction and support recovery. Following the 2019–2020 Australian megafires, we estimated population losses and recovery in fire‐affected fauna, to inform conservation status assessments and management.

Location

Temperate and subtropical Australia.

Time period

2019–2030 and beyond.

Major taxa

Australian terrestrial and freshwater vertebrates; one invertebrate group.

Methods

From > 1,050 fire‐affected taxa, we selected 173 whose distributions substantially overlapped the fire extent. We estimated the proportion of each taxon’s distribution affected by fires, using fire severity and aquatic impact mapping, and new distribution mapping. Using expert elicitation informed by evidence of responses to previous wildfires, we estimated local population responses to fires of varying severity. We combined the spatial and elicitation data to estimate overall population loss and recovery trajectories, and thus indicate potential eligibility for listing as threatened, or uplisting, under Australian legislation.

Results

We estimate that the 2019–2020 Australian megafires caused, or contributed to, population declines that make 70–82 taxa eligible for listing as threatened; and another 21–27 taxa eligible for uplisting. If so‐listed, this represents a 22–26% increase in Australian statutory lists of threatened terrestrial and freshwater vertebrates and spiny crayfish, and uplisting for 8–10% of threatened taxa. Such changes would cause an abrupt worsening of underlying trajectories in vertebrates, as measured by Red List Indices. We predict that 54–88% of 173 assessed taxa will not recover to pre‐fire population size within 10 years/three generations.

Main conclusions

We suggest the 2019–2020 Australian megafires have worsened the conservation prospects for many species. Of the 91 taxa recommended for listing/uplisting consideration, 84 are now under formal review through national processes. Improving predictions about taxon vulnerability with empirical data on population responses, reducing the likelihood of future catastrophic events and mitigating their impacts on biodiversity, are critical.