Climate change threatens the future of rain forest ringtail possums by 2050

Aim: The increasing frequency and intensity of extreme weather escalate the pressure of global warming on biodiversity. Globally, synergistic effects of multiple components of climate change have driven local extinctions and community collapses, raising concern about the irreversible deterioration of ecosystems. Here, we disentangle the pressure of increasing warming and frequency of extreme heatwaves on the population dynamics of tropical ringtail possums (family: Pseudocheiridae). Location: The Australian Wet Tropics World Heritage Area. Method: Ringtail possums' population dynamics were estimated between 1992 and 2021 using a hierarchical population model that explicitly described the state process and accounted for imperfect detection. Under our model, we propagated the estimated mechanisms governing the system by forecasting ringtails' population dynamics between 2022 and 2050. Derived from this process, we calculated the probability of absolute and quasi-extinction using different population viability thresholds. Results: We find a strong negative effect of climate change on population dynamics, particularly extreme heatwaves, resulting in a rapid and severe decline in ringtails' population size in the last three decades. Main Conclusions: Forecasted increases in temperature and heatwaves threaten the collapse of rain forest ringtail possums by 2050, with populations falling below viability thresholds within three decades

Long-term changes in populations of rainforest birds in the Australia Wet Tropics bioregion: a climate-driven biodiversity emergency

Many authors have suggested that the vulnerability of montane biodiversity to climate change worldwide is significantly higher than in most other ecosystems. Despite the extensive variety of studies predicting severe impacts of climate change globally, few studies have empirically validated the predicted changes in distribution and population density. Here, we used 17 years (2000–2016) of standardised bird monitoring across latitudinal/elevational gradients in the rainforest of the Australian Wet Tropics World Heritage Area to assess changes in local abundance and elevational distribution. We used relative abundance in 1977 surveys across 114 sites ranging from 0-1500m above sea level and utilised a trend analysis approach (TRIM) to investigate elevational shifts in abundance of 42 species. The local abundance of most mid and high elevation species has declined at the lower edges of their distribution by >40% while lowland species increased by up to 190% into higher elevation areas. Upland-specialised species and regional endemics have undergone dramatic population declines of almost 50%. The “Outstanding Universal Value” of the Australian Wet Tropics World Heritage Area, one of the most irreplaceable biodiversity hotspots on Earth, is rapidly degrading. These observed impacts are likely to be similar in many tropical montane ecosystems globally