EMR doi: 10.1111/emr.12403 INTERVIEW Some personal reflections on the present and future of Australia’s fauna in an increasingly fire‐prone continent By Chris Dickman and Tein McDonald Australia already has the highest rate of species loss of any region in the world, yet the risks suddenly worsened in the spring–summer of 2019–20, with an unprecedented chain of wildfires covering 10 M ha of the nation’s forest and woodland estate. Fires of this scale were unprecedented and not factored into recovery plans for Threatened Species or ecosystem management in general. EMR asks one of Australia’s most pre‐eminent ecologists what can be done Figure 1. Professor Chris Dickman is pictured here releasing an eastern quoll at Booderee to ameliorate the losses and National Park, NSW, with David Smith. Chris has been involved in studying fauna in Australian ecosystems for over four decades, guiding many cohorts of honours and post‐graduate students better avoid and respond to and earning widespread recognition from his peers. His unequivocal statements regarding the such impacts occurring in potential impact of, and appropriate responses to, the 2019–20 Australian wildfires have been cru- the future? cial in assisting agencies, organisations and communities prepare for timely post‐fire actions and to work towards improved environmental disaster planning. (Photograph: Judy Dunlop). Key words: ecosystem recovery, environmental disaster planning, fragmentation, Threatened Species, published researcher holding wildfire. M: Chris, you were the many highly prestigious roles as Tresearcher who broke the Chris Dickman is Professor in Terrestrial Ecol- a scientist and are not prone to news to the world about the ogy, School of Life and Environmental Sciences, exaggerated statements. Yet, you extent of predicted loss of native The University of Sydney (NSW 2006, Australia, suggest this may even be an animals in the 2019–20 Tel: +61 2 9351 2318; Email: Email: chris.dick- underestimation? Australian bushfires – 800 M in [email protected]). Tein McDonald is Editor D: The initial figure that I calcu- NSW alone and over 1 billion of the journal Ecological Management and Rest- Clated was 480 million in New South Australia‐wide. You are a highly oration (Email: [email protected]). ª 2020 Ecological Society of Australia and John Wiley & Sons Australia, Ltd ECOLOGICAL MANAGEMENT & RESTORATION 1 Ecological Society of Australia EMR INTERVIEW Wales (NSW). That drew on data col- reptiles in the path of the fires. So lated in 2007 for a report prepared the numbers were huge and certainly for WWF (World Wide Fund for Nat- quite shocking when I first estimated ure), to estimate the effects on native them, but still an underestimate as animals of legally approved land clear- more than 6.25 million ha overall ing for development in NSW. The had burned, and other animal groups State of New South Wales had were not included in the calculations. approved the clearing of 640,000 ha of land between 1998 and 2005, TM: So this calculation is which seemed an extraordinary assuming that there would be amount (Fig. 1). few able to survive in refugia in To try to get a handle on it, we the fire grounds, and if they did looked at as much of the published survive the fire, they would not information and unpublished studies be able to survive the post‐fire that we could find on the densities lack of food and habitat? Figure 2. Small mammals are among the of mammals, birds and reptiles in for- CD: Yes. In the first statement I put many vertebrate species that are highly vul- ests and woodlands in the areas sub- out, I used the word ‘affected’. The nerable to the immediate effects of fires as ject to clearing – and to synthesise it reason for doing that was to provide well as secondary effects of lack of food and to produce some average density esti- a little bit more nuance, because if increased predation that occur after fire. mates for those three vertebrate you say that 480 million animals had Widespread fire that leaves few unburnt refuges is likely to place populations of many groups. Once we had that, we could been killed in the fires then everyone fauna species, particularly those already derive the numbers of animals killed assumes that the fires had just inciner- listed as Threatened, at hugely greater risk by multiplying out the average density ated the animals straight out. I wanted of extinction. Much of the wet forest habitat by the area approved for land clearing to avoid that impression. While some of this Endangered silver‐headed antechinus – and that turned out to be 104 mil- animals will be killed immediately in was burnt in early 2020. (Photograph: Gary lion. With the bushfires going on the fires, there will be a lot that had Cranitch). and being as severe and intense and gone underground, into burrows, into covering as much of the landscape cracks in the soil, maybe even some as they were, it seemed that here into tree hollows in the tops of trees. was another huge disturbance event They will survive the immediate that survive in situ are going to be in many ways similar to land clearing. impact of the flames, but then they the less mobile things, small mammals That is, the fire was likely to kill all the will emerge into a burnt landscape perhaps, lizards with deeper burrows. animals in its direct path and the with no resources. Many of them are They are the ones that will emerge extent of it gave little chance of ani- likely to starve or be preyed upon. I into the burnt landscape and face mals that had survived the flames sur- have been in post‐fire environments the prospect of no resources. Already viving in the post‐fire environment prior to the current one and looked at the end of a long drought, they (Fig. 2). Many animals are likely to around and have seen the carcasses were stressed to begin with and, par- die of starvation or predation. of newly dead animals, everything ticularly after the fires had been I came out with the initial figure of from kangaroos through to lyrebirds through and removed food, water 480 million for NSW in mid‐Decem- and even things like bush rats – not and shelter resources, they were not ber 2019 when the fire had burnt 3 burnt but just dead, presumably hav- going to last long. million ha in NSW – the vast majority ing starved. There is an additional factor for of which was forest and woodland. I The key thing about these fires, those survivors and that is that red had to revise this up to 800 million occurring as they did in such dry con- foxes and feral cats move into burned when the fires had burnt 5 million ditions, is that they seemed to be so areas very quickly. They are much ha by the end of 2019. When you big that they were not leaving many more mobile than all of these smaller add just the additional land burned unburnt patches in the landscape to or medium‐sized native species, and in Victoria, let alone other states, the act as refuges for fauna and sources they will come in to pick off the sur- total area burnt came to 6.25 million of recolonisation after the fire (Fig. 3). vivors. We know this from previous ha. Assuming density estimates similar We know from other fires that studies in forest environments and in to those in NSW, particularly in simi- there are probably two groups of sur- open desert environments; these lar habitats just over the border in Vic- vivors, those that survive in situ in the predators are very active and very toria, you end up with an estimate of burnt areas and those that can survive mobile, taking advantage very quickly over a billion mammals, birds and by fleeing into unburnt areas. Those after the fires have gone through. 2 ECOLOGICAL MANAGEMENT & RESTORATION ª 2020 Ecological Society of Australia and John Wiley & Sons Australia, Ltd EMR INTERVIEW The more mobile survivors that charismatic, maybe smaller, maybe might be able to flee are going to be underground and still being burnt, or the birds and the larger more mobile being burnt inside logs or tree hol- animal groups like kangaroos. While lows. It was thinking about all of some individuals may escape the these other unseen animals that moti- flames, many will be disoriented in vated me to draw people’s attention the smoke and flames and die in big to the greater extent of the catastro- numbers. There were images from phe. It was not just the cute and the beach areas down the south coast charismatic ones that were dying, tra- and at Mallacoota showing large num- gic though that must be. It was every- bers of dead birds, for example. But thing else as well. It was about the for those birds that do flee the flames, impact on all the other species and it is going to be very difficult for any on the ecosystems they belong to. to find a place to settle. Studies of land clearing have shown that’s exactly TM: The loss of genetic diversity what happens with birds. They don’t among some fauna species is all die when the bulldozers come extremely concerning. When we through with chains. Some will fly already have under‐represented away to a neighbouring bush block, fauna and conservation requires but very few will survive because as much genetic representation the resident birds, particularly the ter- in as many populations as ritorial ones, won’t have a bar of it.