Deepening droughts and unprecedented wildfires are at the leading edge of climate change. Such events pose an emerging threat to species maladapted to these perturbations, with the potential for steeper declines than may be inferred from the gradual erosion of their climatic niche. This study focused on two species of amphibians—Philoria kundagungan and Philoria richmondensis (Limnodynastidae)—from the Gondwanan rainforests of eastern Australia that were extensively affected by the “Black Summer” megafires of 2019/2020 and the severe drought associated with them. We sought to assess the impact of these perturbations by quantifying the extent of habitat affected by fire, assessing patterns of occurrence and abundance of calling males post‐fire, and comparing post‐fire occurrence and abundance with that observed pre‐fire. Some 30% of potentially suitable habitat for P. kundagungan was fire affected, and 12% for P. richmondensis. Field surveys revealed persistence in some burnt rainforest; however, both species were detected at a higher proportion of unburnt sites. There was a clear negative effect of fire on the probability of site occupancy, abundance and the probability of persistence for P. kundagungan. For P. richmondensis, effects of fire were less evident due to the limited penetration of fire into core habitat; however, occupancy rates and abundance of calling males were depressed during the severe drought that prevailed just prior to the fires, with the reappearance of calling males linked to the degree of rehydration of breeding habitat post‐fire. Our results highlight the possibility that severe negative impacts of climate change for montane rainforest endemics may be felt much sooner than commonly anticipated under a scenario of gradual (decadal‐scale) changes in mean climatic conditions. Instead, the increased rate of severe stochastic events places these narrow range species at a heightened risk of extinction in the near‐term.
Montane ecosystems cover approximately 20% of the Earth's terrestrial surface and are centres of endemism. Globally, anthropogenic climate change is driving population declines and local extinctions across multiple montane taxa, including amphibians. We applied the maximum entropy approach to predict the impacts of climate change on the distribution of two poorly known amphibian species (Philoria kundagunganandPhiloria richmondensis) endemic to the subtropical uplands of the Gondwana Rainforests of Australia, World Heritage Area (GRAWHA). Firstly, under current climate conditions and also future (2055) low and high warming scenarios. We validated current distribution models against models developed using presence-absence field data. Our models were highly concordant with known distributions and predicted the current distribution ofP. kundagunganto contract by 64% under the low warming scenario and by 91% under the high warming scenario and thatP. richmondensiswould contract by 50% and 85%, respectively. With large areas of habitat already impacted by wildfires, conservation efforts for both these species need to be initiated urgently. We propose several options,including establishing ex-situ insurance populations increasing the long-term viability of both species in the wild through conservation translocations.
In the last several decades, habitat loss, overexploitation, invasive organisms, disease, pollution and, more recently, climate change have led to catastrophic declines in amphibian biodiversity. Montane amphibian species, particularly those with narrow distributions and specific habitat requirements are likely to be at particular risk under future climate change scenarios. Despite this, fundamental ecological data are lacking for most of these species. Philoria kundagungan is a poorly known representative of a range-restricted genus of montane amphibians from eastern Australia. Using an occupancy framework, we conducted repeated call playback surveys at 32 sites across the mountainous regions of south-east Queensland and north-eastern New South Wales, Australia, to investigate: (1) the current extent of this species’ geographic range, and (2) environmental predictors of this species’ presence. We found that P. kundagungan has a highly restricted and fragmented distribution, being limited to ~11 km2 of potentially suitable habitat, and that its presence is strongly associated with high elevation (>800 m). Our survey protocol resulted in a high probability of detection (>70%) at occupied sites from relatively few visits. From these baseline data, future studies will have the ability to determine changes in this species’ geographic range and occupancy rate in response to the ever-increasing threats faced by P. kundagungan, thereby supporting more effective conservation strategies and policy decisions.
Amphibians are the most endangered class of vertebrate on Earth. Knowledge of their ecology is crucial to their conservation; however, many species have received scant attention from researchers, particularly in regions that are difficult to access or when traditional monitoring methods are impractical. In recent years, technological advancements in environmental audio collection techniques and signal detection algorithms (i.e., call recognition) have created a new set of tools for examining the ecology of amphibians. This study utilises these recent technological advancements to examine the calling phenology of a poorly known Australian mountain frog (Philoria kundagungan). Audio recordings and meteorological data were collected from six localities across the species range, with recordings made every hour for ten minutes between July 2016 and March 2018. We developed an audio recognition algorithm that detected over 1.8 million P. kundagungan calls in 8760 h of audio recordings with a true positive rate of 95%. Our results suggest that calling activity was driven by substrate temperature and precipitation, which has potential consequences for the species as the climate warms and seasonal precipitation patterns shift under climate change. With this detailed knowledge of P. kundagungan calling phenology, this difficult-to-find species will now be more reliably detected, removing a barrier that has hindered efforts to study and conserve this species.
The 2019/20 Australian megafires impacted numerous species, including six of the seven montane frog species from the genus Philoria, which are restricted to the top of mountain habitats across eastern Australian Gondwana Rainforest. Using single nucleotide polymorphisms, we examined the population structure and genetic diversity of the six Philoria species to inform conservation management and assess their capacity for post-fire recovery. Narrow-range species were confirmed as a single population for management purposes, while P. kundagungan, P. loveridgei, and P. sphagnicolus exhibit marked genetic differentiation between populations, indicating strong allopatric differentiation among populations isolated on separate mountaintops, suggesting limited natural dispersal ability. We further identify high-value genetic populations in these structured species. Populations that were heavily impacted by the fires, such as P. pughi and P. knowlesi, may face longer-term threats due to potential declines in adaptive capacity. We recommend prioritising in situ management, genetic rescue, and translocation efforts to bolster resilience in isolated populations. Updated conservation planning and targeted fire buffer management are crucial for the survival of these ancient, regionally endemic frogs in a rapidly changing climate.