Dr Kaya Klop-Toker

With large wildfires becoming more frequent1,2, we must rapidly learn how megafires impact biodiversity to prioritize mitigation and improve policy. A key challenge is to discover how interactions among fire-regime components, drought and land tenure shape wildfire impacts. The globally unprecedented3,4 2019¿2020 Australian megafires burnt more than 10 million hectares5, prompting major investment in biodiversity monitoring. Collated data include responses of more than 2,000 taxa, providing an unparalleled opportunity to quantify how megafires affect biodiversity. We reveal that the largest effects on plants and animals were in areas with frequent or recent past fires and within extensively burnt areas. Areas burnt at high severity, outside protected areas or under extreme drought also had larger effects. The effects included declines and increases after fire, with the largest responses in rainforests and by mammals. Our results implicate species interactions, dispersal and extent of in situ survival as mechanisms underlying fire responses. Building wildfire resilience into these ecosystems depends on reducing fire recurrence, including with rapid wildfire suppression in areas frequently burnt. Defending wet ecosystems, expanding protected areas and considering localized drought could also contribute. While these countermeasures can help mitigate the impacts of more frequent megafires, reversing anthropogenic climate change remains the urgent broad-scale solution.

The climate crisis adds multiple threats to the already long list of stressors on global biodiversity. The result is a paucity of resources and a growing list of species in need of conservation programs to secure their future. Conservation actions that deal with persistent and pervasive threats must focus on trying to understand the biology of the organism, its ecology and response to such threats without being paralysed by inaction due to gaps in knowledge. Following the devastating 2019/20 mega-fires across the east coast of Australia, a major effort to combine complementary conservation approaches to monitor and recover populations of threatened amphibians was mobilised. For one species, the cryptic Littlejohn's tree frog (Litoria littlejohni), this integrated conservation framework combined traditional ecological approaches including population monitoring, habitat creation, captive breeding and translocation, with established and emerging biotechnologies such as genetic analysis, biobanking, assisted reproduction and biomarkers of individual health. Littlejohn's tree frog was recently uplisted to Endangered, due to increased threat of extinction resulting from the fires, whilst already suffering from disease and reduced genetic diversity. Our integrated conservation approach attempts to accelerate recovery of a species threatened with multiple landscape persistent stressors that are not mitigated by singular conservation actions. Presented here as a case study, we argue this integrated approach used for Littlejohn's tree frog could be adopted for other species facing perilous population declines.

Aim: Changes to the extent and severity of wildfires driven by anthropogenic climate change are predicted to have compounding negative consequences for ecological communities. While there is evidence that severe weather events like drought impact amphibian communities, the effects of wildfire on such communities are not well understood. The impact of wildfire on amphibian communities and species is likely to vary, owing to the diversity of their life-history traits. However, no previous research has identified commonalities among the amphibians at most risk from wildfire, limiting conservation initiatives in the aftermath of severe wildfire. We aimed to investigate the impacts of the unprecedented 2019¿2020 black summer bushfires on Australian forest amphibian communities. Location: Eastern coast of New South Wales, Australia. Methods: We conducted visual encounter surveys and passive acoustic monitoring across 411 sites within two regions, one in northeast and one in southeast New South Wales. We used fire severity and extent mapping in two multispecies occupancy models to assess the impacts of fire on 35 forest amphibian species. Results: We demonstrate a negative influence of severe fire extent on metacommunity occupancy and species richness in the south with weaker effects in the north¿reflective of the less severe fires that occurred in this region. Both threatened and common species were impacted by severe wildfire extent. Occupancy of burrowing species and rain forest specialists had mostly negative relationships with severe wildfire extent, while arboreal amphibians had neutral relationships. Main Conclusion: Metacommunity monitoring and adaptive conservation strategies are needed to account for common species after severe climatic events. Ecological, morphological and life-history variation drives the susceptibility of amphibians to wildfires. We document the first evidence of climate change-driven wildfires impacting temperate forest amphibian communities across a broad geographic area, which raises serious concern for the persistence of amphibians under an increasingly fire-prone climate.

The status of many amphibian populations remains unclear due to undetected declines driven by disease and difficulties in obtaining accurate population estimates. Here, we used genome complexity reduction-based sequencing technology to study the poorly understood Littlejohn's treefrog, Litoria littlejohni across its fragmented distribution in eastern Australia. We detected five identifiable genetic clusters, with moderate to strong genetic isolation. At a regional scale, population isolation was likely driven by population crashes, resulting in small populations impacted by founder effects. Moderate genetic isolation was detected among populations on the Woronora Plateau despite short distances between population clusters. Evidence of recent declines was apparent in three populations that had very small effective population size, reduced genetic diversity and high inbreeding values. The rates of inbreeding detected in these populations combined with their small size leave these populations at elevated risk of extinction. The Cordeaux Cluster was identified as the most robust population as it was the largest and most genetically diverse. This study exemplifies the value of employing genetic methods to study rare, cryptic species. Despite low recapture rates using traditional capture-recapture demographic methods, we were able to derive population estimates, describe patterns of gene flow, and demonstrate the need for urgent conservation management.

Conservation managers cannot manage what they don't know about, yet our existing biodiversity monitoring is idiosyncratic and small in scale. One of Australia's commitments to the Convention for Biological Diversity in 2015 was the creation of a national biodiversity monitoring programme. This has not yet occurred despite the urgent need to monitor common and threatened species, as highlighted by the challenges of determining the biodiversity impacts of the Black Summer fires of 2019/20. In light of improvements to automation, miniaturisation and powering devices, the world urgently needs to scale-up biodiversity monitoring to become coordinated, comprehensive and continuous across large scales. We propose the BIOMON project that could achieve this where individual sensor nodes use machine learning models to identify biodiversity via sound or photos onboard. This could be coupled with abiotic data on temperature and humidity, plus factors such as bushfire smoke. Nodes would be set within networks that transmit the results back to a central cloud repository where robust analyses are conducted and provided free to the public (along with the raw data). Network arrays could be set up across entire continents to measure the change in biodiversity. No one has achieved this yet, and significant challenges remain associated with training the algorithms, low power cellular network coverage, sensor power versus memory trade-offs, and sensor network placement. Much work is still needed to achieve these goals; however we are living in the 21st Century and such lofty goals cannot be achieved unless we start working towards them.

Since the introduction of the term "rewilding" in 1998, several definitions have been proposed, sparking debate around terminology and how (or if) rewilding differs from restoration. Many papers attempt to distinguish between the two terms through a series of descriptive attributes: historic baselines, landscape-driven transformation, ongoing human intervention, the connection of people with nature, and the creation of novel ecosystems. Here, we discuss the overlap between these terms and illustrate that the creation of novel ecosystems provides the clearest distinction between rewilding and restoration. If the definition of rewilding is distilled down to its most unique component, the creation of novel ecosystems, perhaps scientists can then work to produce a clear framework for rewilding that is based on best conservation practice.

The 'Compassionate Conservation' movement is gaining momentum through its promotion of 'ethical' conservation practices based on self-proclaimed principles of 'first-do-no-harm' and 'individuals matter'. We argue that the tenets of 'Compassionate Conservation' are ideological - that is, they are not scientifically proven to improve conservation outcomes, yet are critical of the current methods that do. In this paper we envision a future with 'Compassionate Conservation' and predict how this might affect global biodiversity conservation. Taken literally, 'Compassionate Conservation' will deny current conservation practices such as captive breeding, introduced species control, biocontrol, conservation fencing, translocation, contraception, disease control and genetic introgression. Five mainstream conservation practices are used to illustrate the far-reaching and dire consequences for global biodiversity if governed by 'Compassionate Conservation'. We acknowledge the important role of animal welfare science in conservation practices but argue that 'Compassionate Conservation' aligns more closely with animal liberation principles protecting individuals over populations. Ultimately we fear that a world of 'Compassionate Conservation' could stymie the global conservation efforts required to meet international biodiversity targets derived from evidenced based practice, such as the Aichi targets developed by the Convention on Biological Diversity and adopted by the International Union for the Conservation of Nature and the United Nations.

Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public.

Invasive fish threaten many native freshwater fauna. However, it can be difficult to determine how invasive fish impact animals with complex life cycles as interaction may be driven by either predation of aquatic larvae or avoidance of fish-occupied waterbodies by the terrestrial adult stage. Mosquitofish (Gambusia spp.) are highly successful and aggressive invaders that negatively impact numerous aquatic fauna. One species potentially threatened by Gambusia holbrooki is the green and golden bell frog (Litoria aurea). However, G.¿holbrooki's role in this frog's decline was unclear due to declines driven by the chytrid fungal disease and the continued co-existence of these fish and frogs in multiple locations. To clarify the extent to which Gambusia is impacting L.¿aurea, we conducted 3¿years of field surveys across a deltaic wetland system in south-east Australia. We measured the presence and abundance of aquatic taxa including G.¿holbrooki, and L.¿aurea frogs and tadpoles, along with habitat parameters at the landscape and microhabitat scale. Generalized linear models were used to explore patterns in the abundance and distributions of L.¿aurea and G.¿holbrooki. We¿found strong negative associations between G.¿holbrooki and tadpoles of most species, including L.¿aurea, but no apparent avoidance of G.¿holbrooki by adult frogs. Native invertebrate predators (Odonata and Coleoptera) were also absent from G.¿holbrooki-occupied ponds. Due to the apparent naivety of adult frogs toward G.¿holbrooki, the separation of G.¿holbrooki and tadpoles, plus the abundance of alternative predators in G.¿holbrooki-free ponds, we conclude that the impact of G.¿holbrooki on L.¿aurea recruitment is likely substantial and warrants management action.

Although amphibians are one of the most threatened animal groups, little published evidence exists on effective management programs. In order for conservation initiatives to be successful, an understanding of habitat use patterns is required to identify important environmental features. However, habitat use may differ between the different sexes and age classes due to different behavioural and resource requirements. For this study, we compared microhabitat use during the active breeding season among the sexes and age classes in the endangered green and golden bell frog Litoria aurea, a species which has had several failed management programs. We found aquatic vegetation was selected for by every L. aurea class, and should be the focus of future management plans for this species. Females were the only class to select for terrestrial vegetation more than availability. Increasing the amount of terrestrial vegetation around ponds may help encourage female occupancy, and possibly improve management outcomes, as they are typically a limiting resource. Although large rock piles have been used in past L. aurea habitat management, they were selected for by adults and juveniles, but not metamorphs. Therefore, large rocks may not be necessary for captive breeding portions of management initiatives, which typically only involve tadpoles and metamorphs prior to release. The results indicate that the most appropriate management plans should contain a habitat mosaic of various microhabitats, such as a large proportion of aquatic and terrestrial vegetation with patches of bare ground and a small proportion of rocks for basking and shelter. Recognizing differences in microhabitat use patterns between individuals in a population and implementing them into management strategies should be a pivotal step in any conservation plan.

Although human-modified habitats often result in a loss of biodiversity, some have been found to serve as habitat refuges for threatened species. Given the globally declining status of amphibians, understanding why some species are found in heavily modified environments is of considerable interest. We used the endangered green and golden bell frog (. Litoria aurea) as a model to investigate the factors influencing their distribution toward industrial areas within a landscape. The number of permanent waterbodies within a kilometer of surveyed sites was the best predictor of L. aurea occupancy, abundance and reproduction. It appears that industrial activities, such as dredging and waste disposal inadvertently created refuge habitat for L. aurea to fortuitously persist in a heavily modified landscape. Future conservation plans should mimic the positive effects of industrialization, such as increasing the number of permanent waterbodies, especially in areas containing ephemeral or isolated waterbodies and threatened with drought. Our findings also suggest that despite amphibians being relatively small animals, some species may require a larger landscape than anticipated. Recognizing life history traits, in combination with a landscape-based approach toward species with perceived limited motility, may result in more successful conservation outcomes. Identifying why threatened species persist in heavily disturbed landscapes, such as industrial sites, can provide direction toward future conservation efforts to prevent and reverse their decline.